A good book on kata in the first instance should initially be a book on kata. A book on a specific kata should be primarily about its given subject. Karate's Supreme Ultimate does have some good insight into Taikyoku – the most rudimentary of karate kata taught to beginners and revisited to reveal the inner secrets of its more advanced successors.
The insight is buried in lessons in the Japanese language, general technique tips, constant references to Musashi's The Book of Five Rings and an extensive glossary. The downfall of all of this is that had I wished to learn Japanese I would have consulted a Japanese teacher, for general technique which works within the system I'm learning I would have asked my instructor and for Musashi I would have cut the middleman and bought that book instead. The glossary however is a great resource. There are similar – maybe even better – glossaries available online at no cost but if you would like one for the bookshelf then I would recommend this one. For everyone else – If you already have a rough understanding of the history of karate (such as it is), know how to make a fist or want to hear a head instructor talk about the grading syllabus in his style then this is a great reference. For people who want an analysis of Taikyoku (as I expected) give this one a miss.
