So, Agus,
search PPrune for one or all of the following
Maun, Namibia, Botswana, Windhoek, Swakopmund, Gaberone
the threads go back to about 2002, and there are 2 or three threads for each year from then to now
there are thousands of posts (it will take you a long time to read it all), go through them all, there is far more information than you imagined you would ever need.
There's a thread, for example, that's everything you want to know about flying in Maun, by lilflyboy, it's an excellent STARTING point.
Then, go read the newspapers for the countries and cities you're thinking about. Then go read about the governments. Get involved in some other forums, there are several that are dedicated to Africa, and in particular African aviation.
Go to the library and get some books on Africa, and read them.
Check out the health statistics.
All of this stuff can be found through google, or the library.
I'm not going to give you a list of links, because this endevour should not be something "handed" to you, it wasn't handed to most of the pilots who are there now.
Good luck.