I've seen it elsewhere in the reviews, and this statement is correct. If you're just starting out in guitar (less than 1 year experience), this is not the book for you.
Ideally the guitarist reading this book should have at least a basic working knowledge of the 7 basic modes (and all the types of chords, scales, and associated arpeggios) , circle of 5ths, and alternate picking techniques.
The book has a ton of great exercieses ( a LOT of chromatic runs) which will help your improve dexterity and 'cleanliness' in picking.
A HUGE bonus is the CD that's included in the back with like 100 tracks, you can actually hear the examples in the book as they are supposed to sound.
If you, as a guitarist, have been stuck in a rut, or are looking to delve into more exotic and cool song structures and such, definately check out this book!
There is so much in this book. I think the best approach is to take it 1 week at a time, and cover a chapter per week. That's what I'm going to attempt!
I myself have been a practicing guitarist since 1996.