The Swahili: Reconstructing the History and Language of an African Society, 8-15

This slim volume is more than just a survey of the East African coast. It is actually the foremost text on the methods and sources available for understanding the continent's remote past. With the Swahili as a test case, Nurse and Spear discuss the major categories of primary sources, along with sound methods for using them. Their findings support the scholarly consensus about the coast: despite significant external contacts, notably from the Indian Ocean, the Swahili (both language and people) are fundamentally African in origin and character. Linguistic data gets special attention, but those sections are less scary than they first appear, since the authors generally succeed in clarifying this complex material and its role in reconstructing African history. T. Spear, "Kenya's Past" achieves the same goal for a whole country, and with greater time depth. But since that work is OP, "The Swahili" is a good option.

The Swahili is a concise and informative book. It is dry and somewhat boring, but the authors do not drag it on longer than it needs to be. If you are looking for a "quick read" on the Swahili, this is it.