Hello. I am moving to Rwanda in March/April 2011.
Do's
Do learn the local language. Kinyarwanda, It is fairly easy once you start to practice it.
Do try and get linked in with as many people as you can. This will help you to broaden your friendships circle.
Do expect to be waiting around A LOT for almost everything.
Do remember that the last Saturday morning of each month is Muganda. It is where all people are expected to help with community cleaning etc. Shops are closed on this morning and it is forbidden to drive. If you want to fit in then get invovled.
Do learn and research the Genocide. It is a massive part of the history of this country and the people.
Dont's
Don't automatically think that everyone who looks at you with a strange look is angry at you. In my experience, a smile or a Muraho(Hello)or Amakuru(How are you) or even a wave changes that look in to a smile. Rwandans are very happy and sociable people.
Don't give in to the barrage of "give me money" or "Agachupa"(water bottle)this mainly comes from the kids. If you give to one then 2 things will happen. Everyone else will want the same and fights WILL break out.
Don't try starting a conversation with someone on French. Because of the French role in the genocide, the country has separated ties with the french.
This is probably the biggest DON'T.
Do not under any circumstances or at any time ask anyone if they are "Hutu" or "Tutsi" Rwandans class themselves as Rwandans or Rwandese now and will be deeply hurt if you ask them what tribe they come from.