It starts with the creation myths, and then chronologically, explains very simply the beginnings and endings of the kingdoms of Ghana, Mali, and Songhaim. It addresses the mingling of the native religion with Islam, and ends with the downfall of the kingdoms. It also briefly addresses the issue of slavery.
I bought this about a month before visiting a friend who is doing research in Bamako (the Capital of Mali). I vaguely recollected learning about a chapter's worth in seventh grade about the Saharan trade routes and something about Ghana and Songhai and Timbuktu, but could not remember much more than the names of the kingdoms.
This book was excellent, in giving me enough background to be able to appreciate the depth of the history and the people when I visited. That being said, this is an excellent place to START learning about West African history - but hopefully, it is not where you will end your learning, as there are other resources out there that give much deeper and more thorough information about this great region.