Baguazhang as a modern day self defense system.
This book and the first book by John Painter are the first books that I have seen that have the primary goal of teaching Baguazhang as a modern day self defense system.
Other books seem to be more focused on the cultural or personal experience aspects. In these books, Dr. Painter combines the effective historical Baguazhang with more recent discoveries in training. And presents them in a very well explained and easy to understand manner.

The two books by Dr. Painter are very well written with lot of pictures and drawings to illustrate the contents.
I also recommend getting the 6 DVDs that Painter made, along with the two books. As good as the books are, it is helpful to watch the techniques demonstrated. Both the books and DVDs are published by Unique Publications and there is more information on the DVDs at Artemis Seminars.

I highly recommend Dr. Painter's Books and DVDs for anyone that wants to learn Baguazang as a modern day self defense martial art.