How should my family prepare for a trip to Kenya?

my64x asked:

My parents and I will most likely be visiting Kenya in December for about two weeks–it will be the first time for each of us. We will be going on a safari through the savanna, encountering wild animals and such. I don’t know any more details other than those, though. It’s a once-in-a-lifetime experience, so we want to make it mostly positive!

We’d like to know if we need to receive any vaccinations and shots, and if so, when to get them. Also, if there’s anything we need to know about Customs, climate, the political situation, etc., that would be wonderful.