I find it odd that, although there is certainly information about M:tG in this node, none of it really explains how the game works, or, more specifically, how to play it.
A lot of the real fun in the game comes from the fact that it requires thinking, and strategy, to play well. There's not a lot of "Look at all my rare, expensive cards as I use them to bash your pathetic human face in" going on, here. In fact, some very nice decks can and have been built using nothing but common and uncommon cards. This makes the whole game dependent less on physical resources (although you'll still need some to get the cards in the first place) and more on mental resources, which is rather nice. So you could theoretically have a deck worth hundreds and still lose if you act like a dipshit.

Magic is great because there's no real set form that you have to have your deck follow to win. That means that you can, in a way, make a deck that follows your playing style (eg; smash face with creatures, eat face with spells, explode face with enchantments) and still be a formidable opponent. Most cards can also be used in combination with other cards to become more effective, although this can be difficult to set up, especially if your opponent knows what you're trying and is trying to stop you.

But some of this makes no sense if you don't know how the cards are set up, so here's where you learn how to play Magic.

BEFORE YOU START
First of all, in order to play, you're going to need a deck and an opponent. I can't help you with the second, but the first is no problem.
Decks need to be at least 60 cards, and for the most part probably should stay at the minimum. One of the things most new players do is take all of their good stuff, and put it into a deck. It doesn't work. Instead, decks should have cards that work together to help you win. Use Crucible of Worlds and Armegeddon to destroy everyone's lands, and then play yours from the graveyard while your opponent struggles to play anything new. Bring out a legion of soldiers and beef them up with Daru Warchiefs. However, keep in mind that you can have a maximum of only 4 of each differently named card in your deck, barring basic lands. There are a few cards that are restriced or banned in certain formats, but it's pretty unlikely you'll come across them if you're just starting out.

It's also important to have ways of dealing with problems you may face in the game. Pack a few Disenchants if the deck is weak against enchantments, or Terrors if you get too overrun by creatures. Of course you can't think of every possible way your opponents may hurt you, but you can stop the more common problems with a little bit of work.

If you're interested in tournament play, you may want to put in a 15 card sideboard as well. Then fill that up with a variety of cards that can shut down decks, and use those if you think you need them. (A sideboard is 15 supplemental cards in the deck that you can swap for other cards at the beginning of the second+ round of a game)

Cards will all be set up in a certain format; they all have a name, mana cost, card type, set symbol/rarity, and card text. Creatures will also have power and toughness noted at the bottom right corner of the card, and some cards also have flavor text, which is just a quote or witty sentence that somehow relates to the card. The mana cost will always follow a specific format; colorless cost, then colored cost. I believe the colors are also shown in a certain order, but that's more trivia than important game factoid. So, a card with a 2 then two little red fireball symbols would cost two colorless and two red mana. Colorless mana is really just a way of saying 'you can pay for this part of the cost with any color mana', while you can only pay the colored mana cost with the respective colored mana.

Card type is important, so much so that I'm giving it its own section a little bit below of this spiel. There are 10 card types: Land, Creature, Artifact, Enchantment, Enchant {Permanent, Land, Creature, Artifact, Enchantment, Equipment, or World}, Instant, and Sorcery, as well as the now-defunct Interrupt (consider these instants).

The Set Symbol is not usually that important in the game, barring a few cards from older sets and a few more from Unhinged, but it is important for tournament play. Most of the time you'll need your cards to be from either the last few blocks, the latest set, or occasionally from only the older sets. However, as long as a card is in one of the newer sets, you can use a copy of it from an older set. So you can use a Fireball from Beta, the second oldest set, in a Type 2, because Fireball was remade in newer sets. It's also important to note that the Set Symbol also contains information on the card's rarity. If the symbol is filled in black, the card is common; silver is uncommon, and gold is rare. Unfortunately this is only true for sets released after Exodus. Of course, Exodus was released in 1998, so the cards you can buy now are probably going to have this feature.

The card's text is obviously the most important part of the card, owing to the fact that it's where the card tells you what it actually does. WoTC has done a decent job of keeping this relatively easy to understand, but older cards get more and more unintelligible as you go back. Unfortunately, card text takes precedence over rules, and just about every basic rule of the game has at some point been broken by a card, and this can cause some confusion among newer players. As a rule of thumb, just remember to do what the cards say. And if two cards clash, use your sense of logic or flip a coin. Hell, it's only a game. It's easier to explain how the card text works in individual card types than it is as a whole, though, so here we go!


TYPES OF CARDS


PERMANENTS

Abilities

Cumulative Upkeep: X
No longer used. (Basically, this ability wasn't printed on cards from the next blocks after its debut) (Thanks, Master Villain)
X in this case is some sort of cost. At the beginning of your upkeep, you put a time counter on the permanent, and then pay the cost once for each time counter on it. If you can't or won't pay the cost, then you sacrifice the permanent.

Phasing
No longer used.
A permanent with Phasing will phase out (be removed from play and put into the phased-out zone) during it's owner's untap phase. All permanents with phasing that are phased out are returned to play at the same time. So, they hop in and out of existence.
Enchantments and Equipment will stay on whatever phases out, so they phase out too. If only the Enchantment or Equipment phases out, it will return to play on the same creature.
Anything that phases out will keep its tokens and counters.

Cycling X
Maybe no longer used.
Cycling can appear on basically any card, including both permanents and nonpermanents.
You can use a card's Cycling ability only if that card is in your hand. To use it, pay the X cost and discard that card from your hand. Then draw a card.
Many cards from the Onslaught block will have additional text that looks something like 'when you cycle (this), you may...". So, when you cycle the card, you may do the additional ability.
There's also a Landcycling offshoot. A card with (Land)cycling makes you search your deck for a (Land) and shuffle instead of drawing a card. Otherwise, it works the same way.
Cycling appeared in the Urza's block and the Onslaught block. Since it reappeared, I'm not sure if it will again, so it's only maybe no longer used.

Echo
No longer used.
On your next upkeep after you play a permanent with Echo, you have to pay its mana cost again or sacrifice it. Once you do, you don't have to pay the cost again.

Fading X
No longer used.
The permanent comes into play with X fade counters on it. At the beginning of your upkeep, you have to remove a fade counter. If the permanent doesn't have any, you sacrifice it.

Kicker X
No longer used.
When you play the permanent or spell, you can also pay the kicker cost. If you do, some added ability will take effect. This ability will be listed on the card, and varies from card to card. Some kickers are very good. Some are very, very bad.

Threshold - X
No longer used.
When you have 7 or more cards in your graveyard, you have threshold. Then, the X on the card will take effect. So a card with Threshold - You win the game. will make you win the game when you have 7 or more cards in your graveyard.

Madness X
No longer used.
When you have to discard a card with Madness from your hand, you may pay the X cost and play it instead. Generally, the Madness cost will be less than the card's normal cost. This was fun to use when you had cards that could make you discard things from your hand.

Affinity for (thing)
No longer used.
Affinity decreases the colorless mana cost for a spell by 1 for each permanent of the type (thing) that you control. It doesn't get rid of the colored mana cost, and it doesn't reduce the colorless cost below zero.
Generally Affinity will be for artifacts. So playing a Broodstar (it costs 8 colorless and 2 blue mana) when you control 7 artifacts would reduce the cost to 3 colorless and 2 blue mana.

Equip X
Equip is only seen on artifacts, so far.
Equipment will also have additional text that looks something like 'Equipped creature gets/gains...'. To equip the equipment, you pay the X cost. You can only equip stuff when you can play a sorcery (unless the card has text like 'BB: Attach this card to target creature'; then it works as an instant).

Imprint
No longer used.
To imprint a card, you remove it from the game. Cards with Imprint are pretty varied, so you have to follow what the card tells you to do. Some cards imprint from your hand, some cards remove from graveyards, and some cards remove stuff from play. The cards will also have text that describes what the imprinted card does when it's imprinted.

Sunburst
No longer used.
Sunburst works differently on creatures and other permanents. When you play the permanent, you put X +1/+1 counters/charge counters on your creature/permanent for each color of mana you used to play it. So if you use one red and two black mana to play something with Sunburst, it will get 2 counters of whatever type.

Types of Permanents
Lands
Lands are the base of any deck. These are what you use to play spells. Think of these as your power source. Without them, you're most likely boned. Not that it's impossible to make a deck that has no mana; it's just very difficult and probably not worth your while.

There are two types of lands; basic and nonbasic. Basic lands are easy to obtain; you get something like 6 of each in each tournament pack you buy. They come in 5 flavors; Plains, Forest, Swamp, Island, and Mountain. They tap for white, green, black, blue, and red mana, respectively. You'll be able to tell what's a basic land and what's not because the more recent basic lands have a big mana symbol in place of any card text. For older cards, it'll say that it adds one of a certain color of mana to your pool.

Nonbasic lands can do a variety of things. Some just tap for two kinds of mana (there's usually some sort of drawback, though), or maybe they tap for 1 colorless and can prevent one damage to something. The only reason there needs to be any distinction is that there's the previously mentioned limit on card duplicates, so while you can have a billion basic lands, you can only have up to four of each nonbasic land. Nonbasic lands are obtained the same way as any other card.

Creatures
Creatures are a pretty common thing to see, probably the second most common next to lands. Normally you'll need at least a few creatures, if only to stop your opponent's, because otherwise you will likely be hacked into tiny pieces fairly quickly. Pretty much every creature can attack and block, barring walls and a few other chaps. When a creature is first played, it will have something called 'summoning sickness', which means that the creature can't attack and can't use any abilities that it taps to activate. This doesn't include abilities that say 'Tap target x', just abilities with the tap symbol before them. Creatures all share one other common trait; some number for power and toughness. Power is how much damage the creature will deal when hitting a player or creature, and toughness is how much damage the creature can take before it dies. Power and toughness can be modified by a large number of spells and enchantments, so don't always expect your big angry monster to remain big and angry the entire game. All damage to a creature goes away at the end of every turn, so a creature with 2 toughness that is dealt only 1 damage per turn will never actually be killed. Generally power and toughness will range from 0-7, but there are some that reach higher numbers. Of course, most creatures will have some sort of ability or power that makes them more useful than the others; otherwise, creatures would just become a pissing match of 'my power and toughness are bigger, eat it', and that would be boring.

There are a very large amount of creature abilities that are actually given a term. For your viewing pleasure, here's a big list of all of them.
First Strike
Basically, when the creature is blocked or blocking another creature, it will deal damage first. So, if your creature is a 5/3 first strike and your opponent's creature is a 3/3, your creature will kill your opponent's before it is dealt damage, keeping it alive. If both creatures have first strike, they still deal damage at the same time, but before any other creatures in combat without it.

Flanking
No longer used.
Whenever your creature becomes blocked by a creature without flanking, the blocking creature gets -1/-1 until end of turn. This happens before damage is dealt, so this can be a lifesaving ability (or a creature-killing ability, if the blocking creature is a pansy).

Flying
A creature with flying can't be blocked by creatures without flying. A creature with flying can block a creature with or without flying. This should be fairly obvious.

Haste
Basically, this means that the creature doesn't come into play with summoning sickness, so it can attack and use tap-requiring abilities the turn it comes into play. Haste does nothing after that first turn.

{Land}walk
Your creature can't be blocked if your opponent has the basic land named in play. So a creature with Islandwalk can't be blocked if your opponent has an Island in play. Can be a useful ability, but is obviously useless if your opponent isn't playing with the right land.

Protection from {thing}
This is a little tricky. Thing in this case can be basically any card type or color, including creature subtypes like Soldier or Zombie.
A creature with Protection from Whatever cannot: be targeted by something that is a Whatever, can't be enchanted by something that is a Whatever, can't be equipped by something that is a Whatever, can't be dealt damage by something that is a Whaever, and can't be blocked by things that are Whatevers.
Being ambiguous sucks. So a creature with protection from white can't be targeted by anything white, or blocked by anything white, or be dealt damage by anything white. It can, however, be destroyed, removed from the game, given -X/-X, or have anything else done to it by something white. Of course, the spell doing these effects will have to work around the protection (in other words, it has to say something like 'all creatures...' and not 'target creature...'). If a creature gains protection from white, any white enchantments on it will just bounce off and go flying into the graveyard. Protection is a little complex, but it's not so bad once you understand what exactly it means.

Shadow
No longer used.
Kind of like flying. Creatures with shadow can only block and be blocked by creatures with shadow. They're in their own little world, so to speak. Creatures with shadow are tricky to work around, since it's most likely you won't have anything with shadow to block them with. But it's also an old ability, so you won't see it often anyways.

Trample
Trample is fun. A creature with Trample will basically mow over anything in its way, as long as it's powerful enough. Or, in more complex terms, if the creature can deal lethal damage to all creatures blocking it, the remaining damage can be distributed among the creatures and the defending player. So a 5/5 with trample that's blocked by a 1/2 will deal 2 damage to the blocker, and then the remaining 3 can go directly to the defending player (or to the already-doomed creature, if for some reason you want to do that instead). So big creatures with trample are scary and have to be dealt with by several creatures or they'll rampage over the puny insects and kill you anyways! It's also good to note that if your trampling creature is blocked by several creatures, you can still assign all of your damage to the one with the lowest toughness and have the rest go through to your opponent. Maximum face-smashing! (Thanks, andersa.)

Banding
No longer used.
Creatures with Banding can band with any other creatures with Banding to form a band while attacking. Bands can also include up to one creature without Banding. The creatures abilities aren't shared, and if any member of band is blocked, all of the members are blocked. However, you get to choose how all damage is dealt by your opponent's creature. This is a pretty fun way to keep your pals alive in combat, and can also be useful for toying with your opponent's head, since blocking a band will save you damage but lose you a creature. It's also worth noting that a defending creature with Banding can decide how all of the damage from the attackers it is blocking is dealt. So, if a creature with Banding blocks a band, then each player decides how their opponent's creatures will deal damage. However, the ability was worded badly and is kind of confusing, so it hasn't seen a lot of play. It probably doesn't help that nothing new has it, either.

Rampage: X
No longer used.
Back to the simpler abilities, now. Rampage means that the creature gets +X/+X for each creature blocking it beyond the first. So a creature with Rampage 2 would get +4/+4 if it was blocked by 3 creature.

Vigilance
This is the brand new shiny term for 'attacking does not cause (this) to tap.'
So, this creature does not tap when it attacks. It still can't attack when you first play it, but it can block after it attacks. This is a fairly useful ability.

Horsemanship
Definitely no longer used.
This little gem is only found in one set; Portal Three Kingdoms.
This is Flying with a different name, basically. Creatures with Horsemanship can block creatures with or without Horsemanship; creatures without Horsemanship cannot block creatures with Horsemanship.

Fear
A creature with Fear can only be blocked by black or artifact creatures. Simple enough.

Morph X
No longer used.
This one is a little complex. You can play a creature with Morph facedown for 3 mana. A facedown morph creature is considered an ability-less 2/2 colorless nameless setless creature-typeless creature.
Then, at any time, you can pay the X cost and flip the creature face-up, turning it into whatever it really is.
Some creatures have additional abilities like 'whenever (this) is turned face-up, give target creature +3/+3'. This can happen multiple times, if the creature is turned facedown again.
Once the creature is morphed up, you can't turn it back into a facedown creature by paying 3 mana again. There are other ways, of course, but that's not really important.

Amplify X
No longer used.
When you play the creature, you may reveal any number of creatures from your hand that share a creature type with the creature you've played. Then, X +1/+1 counters on the creature for each creature revealed. So, if you play a Soldier with Amplify 2 and reveal 3 creatures that are soldiers from your hand, you would put 6 +1/+1 counters on the creature you just played.

Double Strike
In combat, your creature will deal first strike damage, and then normal damage. So a 2/1 creature with Double Strike that's blocked by a 1/3 creature will deal 2 damage, and then another 2. The blocking creature will deal 1 damage after the first 2 damage, so both creatures will die.

Provoke
Possibly no longer used.
When your creature attacks, you may untap a defending opponent's creature and force it to block yours, if it can. You can Provoke a creature that cannot block, too, but it still won't block.
There haven't been any creatures with Provoke in the newest set, but Wizards said they might bring it back, so Provoke is possibly no longer used.

Modular X
No longer used.
When your creature comes into play, you put X +1/+1 counters on it. When your creature is put into the graveyard, you may distribute all of the +1/+1 counters that were on the creature to any number of other artifact creatures.

Bushido X
Inevitably no longer used.
When your creatures blocks or becomes blocked, it gets +X/+X. That's it.
This ability is inevitably no longer used because, although it will probably continue on for the rest of the Kamigawa block, it seems unlikely that it will move on into the next set.

Soulshift X
Inevitably no longer used.
When your creature is put into the graveyard from play, you may return a Spirit creature with a converted mana cost X (converted mana cost just turns each colored mana symbol to 1 colorless mana and adds up the numbers, so 1 red and 1 colorless is 2 for a converted mana cost) from your graveyard to your hand.
Technically the creature could return itself, but the always seems to be 1 less than the creature's converted mana cost. This is probably not a coincidence.

Defender
Your creature can't attack.


Enchantments
Enchantments are permanents that have give some sort of added effect or ablity to something. Enchantments come in two flavors: Enchantment and Enchant (Permanent type).
Enchantments usually give some sort of global effect to the game, like 'All white creatures gain +1/+1'. Others will give you an ability, like 'Pay 1 life: Prevent all combat damage that would be dealt to target creature this turn.'
Enchant (Permanent type)s are played directly on to something. They give some sort of modifier to the card they're enchanting, which can be good or bad depending on what the enchantment is.
Enchant Worlds are now dead, but are basically Enchantments. The catch is that there can be only one Enchant World in play at any time. If a new one is played, the old one is destroyed and put into the graveyard.
Enchantments aren't always crucial to every deck, so it's quite plausible to just leave them out. However, they can also be very effective and useful, so you have to use your best judgement when you're building your deck. Mental resources, remember?

Artifacts
Artifacts are permanents that cost only colorless mana. There are artifact creatures as well, which are just creatures that only cost colorless mana.
Artifacts generally have some sort of ability with some sort of cost. Then you pay the cost and the ability takes effect and something interesting happens. I would like to be more specific, but artifacts can really do anything. They deal damage, return stuff to people's hands, destroy things, create things, get torn into pieces and tossed at things, as well as all sorts of other stuff.
Artifacts are nice because you can include them in basically any kind of deck, because they're colorless and thus can be played with any sort of mana. Many of them don't lean towards any one kind of generic deck, either. They're probably the most versatile kind of permanent you can put into a deck.


NONPERMANENTS

Abilities

Buyback X
No longer used.
When you play the spell, you may pay an additional X colorless mana. If you do, you return the spell to your hand when its effects occur instead of putting it into your graveyard.

Flashback X
No longer used.
When the spell is in the graveyard, you can pay X to play it from your graveyard. When its effects occur, remove it from the game instead of putting it back into your graveyard.

Storm
No longer used.
When you play a spell with Storm, you put a copy of it on the stack for each other spell played that turn. Basically, this means the effect will be multiplied by the number of spells played total, including itself. You can have each copy have a different target, if you would like.

Entwine X
No longer used.
Spells with Entwine will always have two effects, and be worded like do X, or do Y. If you pay the Entwine cost, you instead do both X and Y.

Scry X
No longer used.
When you play the spell, you can look at the top X cards of your library. You can then rearrange them in any order, and put any of them at the bottom of your deck in any order.

Splice onto X Y
When you play a spell with a type X, you may pay Y, reveal this spell from your hand, and copy this spell's text box onto the other spell. The spell you originally played will be discarded after use, but the card you spliced onto it is returned to your hand.
So if you splice Tim (Punch your opponent in the face until he or she falls unconscious, Splice onto Arcane 2) onto a Desperate Ritual (Add 3 red mana to your mana pool), you will reveal Tim, pay 2, and then add 3 red mana to your mana pool and punch your opponent in the face until he or she falls unconscious. If your opponent counters the Desperate Ritual, then you will not be able to punch them in the face until they fall unconscious. Sorry.


ZONES
There are 6 'zones' in the game; library, hand, graveyard, in play, stack, and removed from game. A few older cards also use the ante zone and the phased-out zone, as well. And card not in one of these zones is considered to be outside the game.
Your library is just your deck. So if a card is in that big stack of cards, that's in the library zone.
In the same fashion, the cards you're holding on to are the cards in your hand; thus, they are in the hand zone.
Your graveyard is where your things go when they're killed or disenchanted or whatever. This is also where spells go when their effects go through or are countered. It's important to note that tokens are removed from the game instead of being put into the graveyard; if they are returned to your hand, they will be removed from the game also.
In play is self-explanatory. Anything that has been played is in play.
The stack is the order in which card effects happen, basically. When you first play a card, it goes on the stack. When it resolves (or is countered), it leaves the stack.
Cards are removed from the game for a variety of reasons, but generally cards will only be removed from the game by other cards.
There is also another zone called 'the absolutely-removed-from-the-freaking-game-forever zone'. This is only utilized by one card (AWOL, from the new joke set Unhinged). It will probably never be seen again.


TURN ORDER
At the begining of the game, both players sideboard whatever they choose into their deck, then shuffle their deck. Decide who goes first in whatever way seems best to you, but preferrably something random. Then, both players draw 7 cards. Under certain conditions, a player can mulligan (shuffle their hand into the deck and get new cards). Generally, there are two ways to decide how mulliganing works; either you can only mulligan if you have all land or no land in your hand (in which case you reveal your hand, redraw 7 cards and then can't mulligan again) or you can mulligan anytime (in which case you just redraw one less card, so 6 then 5 then 4 and so on if you repeatedly mulligan). If you're playing casually, it's fine to blend both, however. Each player starts the game at 20 life. Then, whoever goes first plays in this order!

Untap
The Untap phase is pretty simple and also pretty self-explanatory. You untap all of your permanents, unless something on a card says not to.
Of course, that doesn't make sense, really.
Basically, your stuff taps for a variety of reasons. When a card is tapped, you turn it sideways. Any abilities that the card has that require it to tap can no longer be used, and and tapped creature can't attack or block. So for the most part, you can't do anything with your tapped permanents. There are a few exceptions (namely, abilities that don't require the card to tap as a cost), but otherwise that's the case. So the Untap phase is important, because you need your stuff untapped in order to use it.
As previously mentioned, Phasing also happens here. I am not entirely sure why WoTC chose this phase for that purpose.

Upkeep
The Upkeep phase is really not anything on its own. In fact, it's completely empty on its own. However, there are many cards that say something to the effect of "during your upkeep...", or "at the beginning of your upkeep..." or whatever. Well, this is your upkeep, and it's right at the beginning of your turn. But this phase will probably just end up being skipped. Mostly.

Draw
Another simple step. You just draw a card. End of story.
'Draw a card' means 'take the top card of your library and put it in your hand', if you're confused. Nothing else to do here.

Precombat Main Phase
This is where a lot of the action in your turn is going to happen.
During this phase, you can play any kind of spell. You can only play one land per turn, but otherwise you can play any number of spells. Of course normal rules still apply (you can't play permanents in response to someone playing a spell, for example) but otherwise here is where you'll be building up your pile of stuff.

Combat Phase
The Combat Phase is divided up into several steps:
Beginning of combat
The only thing that can really happen here is someone playing an instant or using a permanent's ability. It should be noted that anyone can play instants or use abilities during any of the steps of this phase.

Declare attackers
In this step, the attacking player says which of his or her creatures are attacking, and then taps them if necessary.

Declare blockers
Now, the defending player chooses which creatures to block, and which creatures to block them.

Combat damage
Now the creatures are out, the battle lines are drawn, and it's time for blood to be spilled.
Both players declare how damage will be split up, if it is being split up (normally when a creature is blocked by two creatures). Then, damage is dealt.
First Strike damage is logically dealt first. Then, all normal damage is dealt simultaneously. This includes both damage to creatures and players. All creatures that have been dealt lethal damage die; all players dealt lethal damage lose.

End of combat
Combat ends. People pack up their stuff, collect their fallen, and retreat to their separate sides.

Postcombat Main Phase
This phase is remarkably like the Precombat Main Phase, only it instead happens after combat. Otherwise, the same rules apply.

End Phase
The End Phase is made up of two steps; end of turn and cleanup.
During the end of turn step, all abilities that happen at the end of a players turn are simultaneously activated. After this point, if a new ability would happen at the end of the active player's turn, it will instead happen on the next players end phase.
During the cleanup step, the active player discards cards down to their maximum hand size (7, by default). Then, all effects that last 'until end of turn' or 'this turn' end. Simultaneously, all damage is removed from all creatures.
Then, the turn ends and the next player in line begins their turn in the same order.
The game will end when one player wins or all of the players except for one lose. A player loses the game when he or she has 0 life, has to draw a card but has no deck, or has 10 poison counters (a dead concept; you accrue poison counters mostly by being hit by certain creatures that give them out). The only way to win the game is by a select few cards that will generally be worded something like "if X, then you win the game."


With any luck you have now mastered the basics of M:tG and can acquire some cards and play with fellow human being. If you don't want to buy cards, there are a few ways to play Magic online for free (Apprentice seems to be the most prominent). If you're brand new I would suggest you buy a preconstructed deck (not a tournament pack) and a few booster packs. Try running the precon a little bit, and then try to add some of the stuff you got in your boosters to it, and see how it works.
Generally the preconstructed decks are okay and are capable of winning against decent opponents. It might be good to study the precon's structure a little bit, because generally they're evened out nicely.
Of course, if you want to just make your own path, that can work just as well. My only advice is to come up with a theme, not a deck that has 50 rares that work well, because then your deck will suck and you will be publically mocked.
The rest is up to you.


Sources:
http://wizards.com/magic/comprules/MagicCompRules041001.doc
My own experience with the game