Teaching the Martial Arts
Instructor : Teaching the Martial Arts, by Dr. Robert Sprackland
Teaching Martial Arts : The Way of the Master, by Sang H. Kim
Instructing the Martial Arts, by Charles Ralph Heck, Jr.
Teaching Martial Arts, by Tony Gummerson
Martial Arts Teachers on Teaching, edited by Carol Wiley
I own all of the above. Of them, the book by Dr. Sprackland is perhaps the best. I don't agree with everything he says, but I'm not supposed to, since he gives a number of good (and occasionally differing) ideas of how to do things. It is refreshing, actually, since he talks from the perspective of his art---and gives ideas that wouldn't work for his style, but do work for others. Very good. Sang H. Kim's book is similar in terms of what he tries to cover, though very different in style----Kim's book reads much like a thesis paper, while Sprackland's is much more conversational. Both are well worth having. The books by Heck and Gummerson are also very good, and go more into learning styles and types than Sprackland's. For people who don't have any background in teaching, the information in these books is exceedingly valuable. (And it's valuable for people who do have a background, also. :) All three books are definitely suggested. If you like the book by Gummerson, you might be interested in the other books by him lower down on this page.
Training Theory for Martial Arts, by Tony Gummerson
Going for Black Belt : Key to Success in the Martial Arts and Combat, by Tony Gummerson
Junior Martial Arts, by Tony Gummerson
Mobility Training for the Martial Arts, by Tony Gummerson
Sports Coaching and Teaching, by Tony Gummerson
Strength Training for the Martial Arts, by Tony
If not, you can use the below search box for attempt to find specific titles not listed above----good luck! (And if you find any other martial arts teaching books that look interesting, please let me know.)