Here is a list of some Japanese sword books.
1. Samurai Sword a Handbook
By J.M. Yumoto. Describes Japanese swords and Japanese history.
2. Japanese Sword : Soul Of The Samurai
By Gregory Irvine. Explains history and figures of Japanese swords.3. The Craft of the Japanese Sword
by Leon Kapp, Hiroko Kapp, Yoshido Yoshihara. A great book to learn about Japanese swords and sword making.4. Shinkage-Ryu Sword Techniques: Traditional Japanese Martial Arts
By Tadashige Watanabe. Describes the Shinkage-ryu techniques by Yague.5. Swords and Samurai
By Philip Steele. This book explains history of China and Japan and both cultures. Reading level: Ages 9-12