Like Warhol, the crazy buzz of artists and stars surrounding the subject matter is often more interesting than posing dandy Cocteau himself: Stravinsky, Genet, Picasso, Radiguet, ... and Sartre, naturally.
The book is as detailed as a biography can be, but I can recommend it only if you are really, really, REALLY into Cocteau - which I realized after the last page, that I wasn't.
The story about his relationship/friendship with Radiguet, cut off by Radigue's death, is perhaps THE most tragic ending of a love-story that I have read, ever..