Well I spent 3 weeks in Uganda last year helping a school in one of the poorer parts.
The main things I encountered were:
EVERYONE is friendly and will say hello to you and be warned, if you shake their hand you will be shaking hands with them for the whole time you talk to them

They LOVE shaking hands for some reason, I was shaking one guys hand for ten minutes while I talked to him.
Watch for pick pockets, although not a massive problem they are about.
Uganda/kenya/rwanda - all of central africa is really beautiful. Go if you're into wild life, you'll have the time of your life there.
The roads are great fun as they're full of holes. Driving there is in a completely different league to ANYTHING you would have experienced anywhere else.
edit - Pictures!
Transport for the masses:
Coming into Kampala (capital of uganda):
Kampala from a hotel I stayed in:
When it rains, it doesn't just pour, the sky literally falls on you. Imagine a swimming pool of water being dropped on you in one go. That's what it's like.
Insects - everything there is about 3 times as big as they are here. The ants were huge, the wasps were huge. A beetle the size of a freaking tennis ball flew into me one night. The wasps are especially huge but unlike here in england, because they don't scavenge for waste food they'll generally leave you alone if you don't bother them. They had nests in the kids class rooms at the school i was at.
That reminds me, if you're prone to being bitten by insects, take bucket loads of insect repellant. And not the normal stuff. 50-100% deet is what you'll need to keep them off. Be careful though as although it'll keep the mozzies off, it melts plastics and makes your hands feel a bit rubbery for an hour or so after applying it so be careful with your camera after putting the stuff on
In the hotel, just be aware you'll wake up each morning to find 5 or 6 lizards on your ceilings/walls. hilarious things.
The beer. My god, if you can get it where you go, drink nile beer. It is immense. Delicious stuff and a pleasure to drink at the end of an evening.
Night life. Unless you're in a tourist resort or area, for gods sake DO NOT GO CLUBBING. I did anyway but it was stupid. The clubs are full of pimps and prostitutes and you can garuntee they all have AIDS, I'm not saying that in an internet lol aids way either. They get violent and since there were regular power cuts in the area I was in it was bloody scary getting back from the club to the hotel in the pitch black (it doesn't help that you can't see the indigenous people either due to their colour

).
Oh dear lord they have some of the most hilarious adverts there, take this picture of an always sanitary towel ad that I saw in a shop window for example

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Will upload some pictures for you to give you an idea of what the non touristy areas are like in a minute once they've been cropped and added to my photo bucket account
