To begin with, I have never been good with instruments, although I admire people, who have their way around them. I've never striven to be able to play an instrument either.
When I downloaded the free version of this book, I was quite frankly surprised - the way the book presents the information is interactive and allows anyone who doesn't know a first thing about playing guitar to actually learn it all by himself.
I particularly like the recap part after every chapter, as it resembles the way modern training courses are usually structured and you can actually go ahead an listen to the suggested artists and check how what you've just learned should ideally sound.
Overall, I'd say that this book is great value for money and is written in an understandable, fun manner.