No, it's not by them. Janet Reitman published a devastating expose of Scientology in Rolling Stone a few years ago. That article led to the book. And it's certainly not approved by the Scientology cult; they are not interested in fair or even-handed coverage because that means acknowledging the bad along with the good. They only want positive PR. Scientologists in good standing are forbidden to read Reitman's book.
I'm reading Inside Scientology right now, and from what I can tell the only reason the Co$ hasn't sued Reitman is because she did extensive research and can back up everything presented in the book. It's not libel if it's true.