This book pretty much repeats what he teaches in his groundwork dvd's and also some of his horsemanship dvd's. If you can follow this book without the DVD's, your wallet will thank you! It can also save you on taking your own notes and is much prettier with full colour photos. In the book itself, Clinton does do a good job trying to explain the technique using words and pictures. He also lists the tools you need, common handler mistakes, common horse problems, troubleshooting and tips for success. The anicdotes from beginners learning the exercises for the first time, also provides additional insight to help the reader. This is great to take to the barn as a quick reference.
However, words are words, and some stuff is left for you to figure out. If you struggle with understanding the techniques via text only, then you may want to purchase his DVD series. Some of the more detailed things he get's into in the videos, including dealing with spooky horses or dealing with highly disrespectful horses are simply not there in the text. It's also nice to see how the various horses react so you know what to expect. But Clinton does his best to sort out the issues you may encounter.
Aside from that, I highly recommend this book for anyone; there are many times when I have borrowed horses wishing that they knew how to do a one rein stop or act more respectful on the ground. Everyone should have a horse that can do these exercises, regardless of which trainer you pick to learn from.