A Security Deposit is money that is laid out to provide a buffer between the first payment and the last payment, to ensure that the person receiving the deposit gets their money and/or compensation.
In the case of an apartment, there is usually a security deposit when you move in. If your apartment is up to par when you move out, you get your deposit back.
I'm moving out of my apartment on Tuesday, so I'm going to provide a few tips on how to recover your security deposit (which is usually a lot of money!), as well as some other moving tips in general. (Concentrate heavily on the kitchen and bathrooms. These are the biggies when it comes to getting your cash back.)
Preparation
Get out your lease, as well as the list of damages you made on your pre-move inspection. Be sure the landlord has a copy as well.
Cleaning
This is the most important step in the process. You need to clean everything. Get your spray cleaner, paper towels, mop, broom, and get to work.
• Kitchen - Be sure all of your cabinets are empty. Clean the countertops, as well as the edges around the sink. Clean inside the sink. If it's stainless steel, a brillo pad works well. If it's porcelain, use Windex or another suitable glass cleaner. Clean the faucets.
Clean the stove thoroughly. Most electric range tops have a seam just below the burners. You can lift the entire range to clean underneath. Do this! They check! Also clean the little metal pan thingies under the burners - scrub with a brillo pad if you must. Get 'em shiny. Make sure the walls around the stove are cleaned of any spatter, and be sure the oven is properly cleaned as well.
Clean out the refrigerator. Before your move, you should be keeping your refrigerated supplies to a minimum. Get yourself a large cooler, and dump everything in it. Clean the inside of the fridge from top to bottom. If your racks are crusty, soak them. Surface clean the outside.
Sweep, then mop the floor.
• Dining Room - Leave your table and chairs until the very last minute, but get everything else out of there as soon as possible. Take down any artwork. If you're anal, you can try to spackle the holes shut yourself, but I wouldn't bother. Once the movers have removed the furniture, mop or vacuum the floor.
• Living Room - Pack up all the small crap lying around on tables and such, and leave the large stuff. Dust! Get as much dust off the furniture as possible. Once you've finished dusting, thoroughly vacuum the carpet. The reason you dust and vacuum is to keep buildup of crap in the carpet to a minumum. Take down any artwork. Again, I'd suggest just leaving the holes.
• Bedrooms - Keep a large, clean box by your bed up until the day of your move. That morning, fold up the sheets on the bed and pack them in the box. Toss in the pillows and the bedskirt as well. Leave nothing but your mattress and box spring. Pack all of your clothes in boxes, but be sure to leave out what you need. Tape up your drawers to prevent them from leaving. (Remember to disassemble the mirror from the dresser!) Once everything is packed and the furniture is gone, vacuum everywhere. Try to leave as few carpet imprints as possible.
• Bathroom - Clean the mirrors well. Make sure the walls around the mirror and sink are clean too. Clean the sink, including the drain plug and faucet. Empty your cabinets, and be sure the insides are well swept. (Don't forget to empty the medicine cabinet!) Be sure to clean the toilet from top to bottom, including the inside of the bowl. Get out your brush and scrub! Clean the edges around the base of the toilet (where it meets the floor), and be sure any caulking is as clean as you can get it. Spray and wipe the tiles or the wall in the shower. Clean the entire bathtub, and the edges around the outside. Take down your shower curtain at the last minute. Once everything else is clean, sweep and mop the floor.
Loose Ends
Get your keys together, and turn them in after your apartment is empty. This includes the mailbox key and the key to the apartment, as well as any duplicates. Be sure to turn the keys in to the landlord and not the new resident, or else you'll be charged for the lock changes.
Take a final inspection of the apartment with your landlord, and have them sign off on it. Get a copy of that document.
Take all of your property with you when you move out, and be sure the apartment is suitable for a new tenant. Ask for your security deposit before you leave. If you don't receive it within a few weeks, write a formal letter demanding it.
That should pretty much cover everything. A happy landlord is more willing to give your money back. Obviously, the holes in the walls are going to cost you, but it won't be too much. (In my case, they didn't even care!)
Good Luck!