Don't waste your time or money on this book. Go with (Tai Chi Touchstones), or (Tai Chi Classics). When I first heard about this book I was mislead about the content. I didn't think it was anything more than the author taking the basic principles and writing small stories about them. You can find the basic principles like sinking the weight or relaxing in a hundred books about Tai Chi Go with the books I listed above if you really want to learn something about Tai Chi.
This book is great supplement for someone who is currently studying tai chi, and for the accomplished tai chi player as a both a review and an aid if they in-turn teach. For me, it is like having my teacher in my back pocket. The book collects all the kinds of observations my teacher makes in class about form, performance, or chi while we're doing it. Gillman takes these little gems of advice and compiles them into wonderful and articulate collection. The subtitle "A string of pearls" is in that spirit and an appropriate subtitle.