This book claims to be "the basics," but definitely throws a lot of information at you all at once, including more unusual scales, and modes.
For me this style of learning works well, and it helped that I was passingly familiar with all the concepts explained. However, I lent the book to my mother, and she was thoroughly confused and disheartened, despite having some formal music education (grade 4), and performing music multiple times a week.
I think it really comes down to how you learn, and if you're a sponge for theory.
One thing that was incredibly frustrating with this book, and the second, was the numerous spelling mistakes, and incorrect diagrams. I don't think there was much editing/proof reading unfortunately.
I also would have liked answers to the exercises, just to be sure I really DID understand the concepts.