I've seen this book on the internet. User reviews tell this book doesn't explain how to apply scales.
You can find downloadable PDF's of this book for free online. You should know that it is definitely not a starting point, though. The book is pure intellectual masturbation. Not once does it say "play this pattern over X chord".
I've been improvising over the pentatonic blues scale for ages and since a week or 3 over the Mixolydian scale. Is there another book I can read that fills the gap between improvising (I can do that) and selecting the right scale/chord?
Something that explains why scales and chords fit together and why certain chords resolve in others.
Get Kostka & Payne's "Tonal Harmony". It's not some Doug Marks DVD, but if you're wanting to know scale-harmony relationships, you're going to have to look into some more serious products, anyway.
I have yet to see a book that ties scalar properties in with harmony to any great effect. I've been thinking of putting one together, with guitarists in mind, but it's a massive undertaking, and I don't have the time this semester.
Inevitably, somebody will mention the Guitar Grimoire books, and while Mr. Kadmon has written a book on "scales and modes", there is very little theory within the book, and where there is theory, it is explained in such a way that I find confusing and unhelpful. I do like the large catalog of scales, though. Unfortunately, there aren't as many as the book makes it look like, as any given page will be full of redundant scale patterns in different positions in every key, which makes up the bulk of the volume.