The Budoshoshinshu, by Daidoji Yuzan

http://fowler.winterstorm.org/texts/Budoshoshinshu/

Bushido: The Samurai Code, by Inazo Nitobe

http://www.gutenberg.org/catalog/world/readfile?fk_files=56682&pageno=1

The Art of Peace (Selected Quotes), by Morehei Ueshiba

http://omlc.ogi.edu/aikido/talk/osensei/artofpeace/

The Art of War (Sonshi.com translation), by Sun Tzu

http://www.sonshi.com/learn.html

The Hagakure, by Yamamoto Tsunetomo

http://www.lyon.edu/webdata/users/jchiaromonte/hagakure.htm

The Book of Five Rings, by Miyamoto Musashi

http://www.samurai.com/5rings/