This book provides a very interesting survey of an area often neglected in discussions of writing systems; indeed, as the author and the preface-writer Tadadjeu indicate, it is often assumed (though not by linguists) that African languages were seldom written before the introduction of alphabets (mainly by European colonisers) in modern times. The material covers the origins and characteristics of a wide range of scripts used to write various African languages.
The main problem with the book involves a considerable element of `Afrocentrism': the recent tendency (especially in the USA and elsewhere in the African diaspora) to exaggerate the role of Africa in world culture, by way of reaction to the previous, often racist down-playing of Africa's contributions to history and intellectual life (and to institutions such as slavery). Examples are the ready acceptance of Bekerie's extreme and often dubious claims about the Ethiopic `abugida' (intermediate between an alphabet and a syllabary), and the seriously exaggerated claims made for the Cameroonian Shu-Mom system (made especially strongly in the preface). Afrocentric pseudo-historical works are cited without any acknowledgment of their highly marginal status. Quasi-mystical notions involving `harmony' and spirituality are foregrounded in places.
There are also some oddities, commencing with the decision to spell the words Africa and African with K rather than C, on the ground that K is the letter normally used for the sound in question in Africa itself. The C-K contrast arises only in the context of the modern use of the roman alphabet, where either letter would serve. The Romans used the form with C because this was how they transliterated all Greek loans which had kappa (K) in the original. Furthermore, and more seriously, the scripts covered include various non-alphabetic systems (syllabaries, the Ethiopic abugida, etc); the title is thus misleading (possibly because alphabet is much the best known of these terms among non-linguists). In addition, some of the systems discussed are not true scripts but are instead semiotic systems not representing specific languages or their words, or even simply art or at best matters of graphic design. This may involve the desire to suggest that pre-modern African societies were more literate than was in fact the case (another manifestation of Afrocentrism). And in more general terms the level of linguistic expertise leaves something to be desired. For instance, the notions of ideograph and logograph are confused, and the comments about the ultimate origins of writing are rather naive and inaccurate.
In sum: while the book is informative on a little-known topic, it must be read with various caveats in mind.