
Here are a few links to sites of interest to Japanese Sword collectors, hobbiests, and scholars, as well layman, martial artists, and anyone who appreciates Japanese history and culture!
Japanese Sword Index: Richard Stein's great site with varied information on nihonto as well as swordsmithing, martial arts, and more.
Nihon-To Message Board: The newest home for disussions of all things Nihonto related.
Japanese Sword Society of the United States: One of the last major sword societies left in the US.
The HIGHLANDER Sword Shopper's Guide: I know it sounds like a fan site for cheesy knock offs, but it has a plethora of great info on both real nihonto and reproduction swords as well as a great forum for discussion.
Japanese Culture Page - About.com: A really cool page devoted to all things Japanese, from swords to tattoos and more!!
Shadow of Leaves: This site has some very nice-looking tsubas and japanese arms, as well as some interesting and useful information.
Satcho: Japanese Sword- Books - Supplies: This is an incredible site for both common books that should be on every sword enthusiast's shelves and for those rare and hard-to-find books. Fair and reasonable prices and a few bargains as well. A definite must-see!!