Well, some of the techniques in the book seem a little dated, but it was made by Stephen LaBerge, and he practically pioneered most of the techniques on this site. Most of the techniques here stemmed off of Stephen LaBerge's work. If anything, it's a good lucid dreaming history lesson. All in all, it's worth a read.

That's not to say that the techniques in the book don't work, they do. But most of the information, and a lot of it more in-depth, can be found on Dreamviews too.