A good website is
Samurai Archives, lots of information on key figures in Japanese history. Hagakure is an interesting read, however it should be put into perspective. It was written at a time when many of the Samurai class had turned into bureaucrats during the Tokugawa Shogunate.
You might also want to check the History Channel to see when they are showing the two hour Samurai special. I believe that it is airing again this Saturday (my tivo is set to record it).
Here are some of the recommended books from the above website:
-Berry, Mary Elizabeth. The Culture of Civil War in Kyôto
-Bottemly, I. & A. P. Hopson Arms and Armor of the Samurai
-Bryant, Anthony Sekigahara 1600
-Cooper, Michael They Came To Japan
-Elison, George Deus Destroyed
-Ellison, George and Bardwell L. Smith, eds. Warlords, Artists, and Commoners
-Hall, John Whitney. Government and Local Power in Japan, 500 - 1700
-Hall, John Whitney. Japan from Prehistory to Modern Times
-Hall, John Whitney and Toyoda Takeshi. Japan in the Muromachi Age
-Hall, John Whitney, Nagahara Keiji and Kozo Yamamura, eds. Japan Before Tokugawa [A highly valuable book - a must-have for the serious student]
-Hall, John W. and Marius B. Jansen (ed.) Studies in the Institutional History of Early Modern Japan
-Hane, Mikiso. Japan, a Historical Survey
-Hane, Mikiso. Modern Japan, a Historical Survey
-Latourette, Kenneth Scott. The History of Japan New York: MacMillan Co., 1968
-Leonard, Jonathan Norton. Early Japan
-Lu, David John. Sources of Japanese History USA: McGraw-Hill Inc., 1974 [A priceless reference for the english-speaking student]
-McCullough, Helen C. The Tale of the Heike Stanford 1988
-Mass, Jeffery P. (ed.) Court and Bakufu in Japan Stanford 1995
- Mass, Jeffery P. and William B. Hauser (ed.) The Bakufu in Japanese History Stanford 1985 [Another 'must-have' for the serious student]
-Mosher, Gouverneur Kyoto: A Contemplative Guide Tuttle 1964
-Nish, Ian. A Short History of Japan New York: Frederick A. Praeger, Inc., 1968
-Perry, Commodore M. C. Narrative of the Expedition to the China Seas and Japan Dover Publications, 2000 [A recent reprint of the original 1856 text - fascinating]
-Reischauer, Edwin O. The Japanese Today USA: Harvard University Press, 1988
-Reischauer, Edwin O. Japan, The Story of a Nation, 4th Ed. New York: Alfred A. Knopf, Inc., 1990
-Reps, Paul. Zen Flesh, Zen Bones Rutland, Vermont: Doubleday, 1989 [Excellent Zen stories, with some interesting historical samurai references]
-Sadler, A. L. The Maker of Modern Japan Tuttle 1989 [A classic that continues to stand the test of time]
-Sansom, George. A History of Japan to 1334 California: Stanford University Press, 1999 [The better of Sansom's works]
-Sansom, George. A History of Japan, 1334 - 1615 California: Stanford University Press, 1996 [An entertaining read, if dated and at times inaccurate]
-Sato, Hiroaki. Legends of the Samurai Woodstock, New York: The Overlook Press, 1995
-Shiba, Ryotaro The Last Shogun: The Life of Tokugawa Yoshinobu Kodansha 1998 [A great read definatly worth checking out]
-Totman, Conrad. Tokugawa Ieyasu, SHÔGUN Union City, California: Heian International Inc., 1990
-Tsunoda, Ryusaku, Wm. Theodore De Bary, Donald Keene. Sources of Japanese Tradition New York: Columbia University Press, 1965
-Turnbull, Stephen. The Samurai - A Military History Japan Library, 1996
-Turnbull, Stephen. Samurai Warfare Arms and Armour Press, 1996
-Turnbull, Stephen. Samurai Warlords Blandford, 1992
-Turnbull, Stephen Samurai Warriors Blandford 1987
-Tyler, Royall (ed.) Japanese Noh Dramas Penguin 1992
-Yamamoto Tsunetomo The Hagakure Kodansha 1983
-Yoshikawa, Eiji. Taikô USA: Kodansha International, Ltd., 1992
Have fun reading