Amazon.com: Reviews for Manga: The Complete Guide: Books: Jason Thompson
The cover makes it look like it's going to focus on the really popular manga such as the 'Shonen Jump' titles... which kind of puts me off it. But the review above says it focusses on all different types so could be interesting.
The manga books I really do like are those written by Frederik L. Schodt. I'd recommend "Dreamland Japan" to anyone interested in learning more about Manga.