Please don't consider this book comprehensive. You can't walk into the field or stall armed with just this and train your horse. It covers four methods of training: clicker training, Parelli, round pen training (Lyons) and Tellington Ttouch. I happen to love all four methods and think they can be used together. This book provides an overview, but you will need other references once you choose one (or more) method that feels right for you.
My suggestion is to choose one of the above and begin at the beginning. Teach your horse to respect you and your space and to regard you as his herd leader, and therefore his safety. That will solve a lot of horse "bad behavior" in itself.
But not everything. And when you need a book on your shelf to reference what to do if your horse won't pick up his feet, or is "cinchy", or cribs.... this is a good one. A VERY good one. But do your homework first. As Pat Parelli says, "Take the time it takes, so it takes less time."