A history of African art (not graphic design contrary to the title) is:

http://guity-novin.blogspot.nl/2010/03/history-of-graphic-design-african-art.html

Interesting websites with artists are:

Feature image generated in Adobe Illustrator AI: African colourful geometric design – after several iterations

There is no Wikipedia on African Graphic Design!!!

A Google search for African typefaces tend to be rather kitsch zebras and unusable. Not the typefaces more commonly used in Africa – these are the common Adobe and Microsoft ones. But African designers have used these with colours in slightly different ways that I have yet to properly analyse.

!!Many images from my own travels to be inserted here.

Textile designs

Zulu House Pattern
Zulu House Pattern
Julio Senna, Brazilian inspired by Africa