Uganda is a country in East Africa, between Kenya, South Sudan, the Democratic Republic of the Congo, Rwanda and Tanzania. Uganda is landlocked unless you count Lake Victoria to the south. Uganda is on the Equator, and is one of the smaller countries in Africa, with an area about the same as the United Kingdom. The capital city and largest (and arguably only "serious") city is Kampala, on the Lake Victoria shores.
I live in the UK, and a friend of mine recently moved from the UK to Kampala in order to be with his fiancée. In April 2012 I visited the country for one week to attend their wedding. I cannot say I know anything concrete about the country as a whole after being there for a week, any more than I can say I know anything concrete about the UK having lived there for my entire life. However, this is what I've got so far:
Talk to your doctor before going to Uganda. For your own safety you'll be injected for hepatitis A, typhoid and some other fun diseases. These injections are free. The accelerated course for hepatitis takes 21 days, so do this early. You will also be vaccinated against yellow fever and given a certificate saying so, which you will need in order to enter the country. Keep that inside your passport. The yellow fever jab costs money. You will also be given a prescription for malaria medication. There are various kinds: some have fewer side-effects than others, but cost more money. You may not need to take a mosquito net if you're staying somewhere that provides them.
Uganda is generally bearably hot, with temperatures comparable with the hottest UK summers (in contrast with, say, India or Dubai, which I would characterise as unbearably hot). During the rainy seasons it rains occasionally and briefly (like, for 30 minutes). "It rained" is an acceptable reason for being late to an engagement. Bring an umbrella. Ideal clothing the rest of the time is loose (linen?) trousers or a long skirt, with a pale-coloured, loose long-sleeved shirt/top. Long clothes will protect you from sun and bugs. Also bring a hat and DEET (the strong stuff). Nobody in Uganda wears shorts as far as I can see. Shoes: sturdy walking sandals. If you plan to do actual walking (like, in the rainforest or something), actual boots might be in order too.
Uganda is very religious (mostly Christian, partially Muslim): avoid revealing clothes and overt heathenism. Homosexuality is a very serious crime in Uganda, and soon to become a capital crime.
Uganda is generally reached by plane; its only international airport is Entebbe International (EBB), which is in Entebbe, a smaller city which is about an hour's drive southwest of Kampala. London Heathrow (LHR) is the most distant airport that Entebbe serves directly and the flight takes about 8.5 hours. Uganda is 3 hours ahead of UTC and does not observe Daylight Saving Time.
Uganda is a former UK colony which gained independence in 1962. Thus, at least in Entebbe and Kampala, everybody speaks a basic level of English and all signs, menus etc. are written in English. Among themselves, Ugandans speak other languages like Luganda and Luo. The further from Kampala you travel, the less English there seems to be. "How are you" and "You're welcome" are greetings. Stick with "Hello" as a greeting; switching things up with "What's up", "Good afternoon" and so on seems to cause slight confusion. Try to avoid idioms, puns and florid metaphors. "Mzungu", a word you will hear very often, means "white person" or "foreigner". It's not derogatory, but I wouldn't buy a T-shirt with it written on (and you will be given that opportunity).
Uganda drives on the left and many of the road signs and markings will be startlingly familiar to British people. There are, however, relatively few of these. There are many petrol stations, some roundabouts, almost no traffic lights and nothing resembling street lighting. Street signs and house numbers are also rather rare; my friend, who now lives with his wife in inner-city Kampala, is not 100% certain that he has a home mailing address to speak of. Uganda has some decent quality highways but the majority of roads are potholed or just lumpy, compacted earth. A good driver will avoid these potholes, hence a joke: "How can you tell when a Ugandan is drunk? He drives in a straight line." Ugandan traffic is dense and highly creative. You will see almost every Highway Code law broken, with the exception of the one about the proper use of the horn: while Ugandans use their horns early and often, it is always for the correct reason, signalling "I am here" to other road users. Accidents (e.g. lorries stuck in ditches) are frequent. Pedestrians should stay alert.
Uganda uses the same power sockets as the UK. Power cuts are frequent.
Currency is the Ugandan shilling (UGX) which are roughly 4000 to the UK pound sterling (GBP). These are quite hard to get hold of outside of Uganda, but I was able to withdraw shillings directly from an ATM at a cost of about £4.50 per time. Stuff, in general, in the very loosest sense, costs around half as much as it does in the UK, or less. Prices in supermarkets and restaurants are fixed; at a craft shop or when about to take a taxi trip there is room for a little negotiation up front. Ugandan haggling is very easygoing relative to other countries.
Uganda is one of those countries which almost completely skipped land-line telecommunications and went straight to cellular. Although my UK phone service provider claimed to provide coverage in Uganda, I couldn't get it to work. It might be simpler to buy a pre-paid Ugandan SIM card once you get there.
The internet is very slow in Uganda and many online services (e.g. music streaming sites) will reject your attempts to use them because your IP address is in a country they don't have legal agreements to stream to. Just spend less time online. It's good for you.
From a tourism perspective there isn't actually much to do or look at in Uganda. (Yet?) There is the source of the Nile river, which is apparently very anticlimactic. There are mountain gorillas, but they are way up in the northern part of the country and critically endangered - which presumably makes them very difficult to locate. There is abundant rainforest, but it looks an awful lot like UK forests except for prettier butterflies, fewer stinging plants, slightly taller trees and the occasional monkey fooling about way off in the distance where you can't see them very easily or get very good photographs. If you like looking at nice round numbers on your GPS unit, which personally I do, the Equator intersects the Kampala-Masaka road about two hours out of Kampala, where there's a nominal monument and a decent cafe. If you are an ornithologist, Uganda is dynamite.
In Kampala itself we found that "local food" was not particularly easy to track down, but it seems to be big chunks of beef/pork/lamb/chicken/goat (goat is nice) roasted and served in gravy with various carbs. "Potato" is ambiguous in Uganda: you have to specify "sweet" or "Irish". There is also rice and matoke (mah-TOE-kee), the latter being a fat green banana served mashed and tasting mainly like potato. Skip the "posho" - it is maize, except somehow made more boring. All the food is quite salty; my friend believes this is due to a historical lack of actual herbs and spices to use for food flavouring.
Tap water isn't drinkable; get bottled. Always make sure you know where your next drink is coming from. Don't drink bottled drinks (e.g. beer, Coke) straight out of the bottle; the bottleneck probably isn't that clean. A glass or straw should be provided. Beer consists of about four major lagers. In order from worst to best in my opinion, these are Club, Nile Special, Tusker and Bell. These all seem to be genuine products of Uganda and are drinkable and cheap, but none of them are really up to the standard of a Czech lager, let alone good British ale. (Tusker beer is not to be confused with Tusky's, which is a supermarket chain in the same country.)
Food arrives very, very slowly. So does the bill, and so does your change after paying. If your party has decided to stop for lunch but you are not hungry, order anyway, because you will be by the time it arrives. Tipping isn't a thing in Uganda. Ugandans rarely seem to have change for more than about 5000 shillings available to hand, so try to keep smaller amounts around as much as possible, even though 1000 shilling notes are invariably tatty and horrible.
Step one in solving a problem in Uganda is always to stop worrying and do nothing for a while. You're at a restaurant and the other half of your party hasn't arrived? Don't call them. Just wait. They'll find it. (Of course, while this relaxed pace is great when you're on holiday, it's not so much use when you're trying to get a bathroom fitted.)
But what is it actually like?
Uganda is very hot and very poor. Its earth is dry orange and so are all its buildings, but the vegetation is a lush dark green, which clashes. Uganda is a working country and Kampala is a working city. There are banks, shopping centres, hotels and scaffolding. The scaffolding is made of wood. People go to work (but don't earn a lot of money), they go to school (but not for very many years), they go to church. The city is very noisy at night, and insects are only half of that problem. There's no revolution going on, no famine, no hurricane. It's just a place with a bunch of people living their lives.
I would call Uganda a "developing" nation, and not in the pejorative sense. It's in progress. It has industries, but could use more taxpayers. It has motor vehicles, but could use emissions standards. It could use better infrastructure: drainage, a more robust electricity supply, less litter in the streets. It has the same density of billboard advertisements as any western country. Products being advertised are (1) mobile phone services (services, not phones themselves) and (2) paint. Cell towers are everywhere. Telecoms must be an insanely rapidly growing market there; I can't imagine what challenges and opportunities those companies must face. There is corruption, I'm told. There are human rights abuses in the north of the country, which I never saw. There's a huge advertising campaign to stop domestic violence. HIV is a problem. Malaria is a problem.
I am not what one would call well-travelled so I have no idea how Uganda compares with most other destinations in the world, let alone other destinations in East Africa such as Tanzania and Kenya, but I don't think Uganda is a place that you go to in order to gawp at the sights and dive into the culture. It's a place you go to to live, or because you have friends there whom you want to see. It's real, I suppose. Very hot, and very poor, and real and in progress.