Understanding Karate Do, Johnston Karate's in-house student training manual, is available as a free online PDF book. It is also available through Amazon and Createspace as a professionally bound and printed trade paperback book, and as a Kindle E-Book. Understanding Karate Do represents years of research, training, and teaching. The book includes a brief history of karate, detailed descriptions of general principles (such as "ma-ai" or the concept of proper fighting distance), as well as lists of techniques, drills, and kata practiced in various karate styles. Understanding Karate Do also has articles on Japanese terminology, physical conditioning, karate precepts and philosophy, and more. Hopefully, it has something for both beginners and experts. Understanding Karate Do is intended to be a useful resource as potential and current students training in karate.