Here is some information I have collected about Japanese garments.

Quick guides:

• JPNET: A quick picture guide to Obi, Yukata, Hakama, and Kimonos. Also has some picture guides to different periods.
• A really quick history
• General information site on kimonos

• A history of Men's Clothing and Accessories. Has a lot of differing garment types, including Kataginu, variations of garments, and some information on appropriate colors for different classes
• The Tale of Genji - Costume Museum: Costume history in japan
  Gallery of pictures from the costume museum - very cool

• The Samurai Archives : Much information on samurai, including family mons, famous samurai, culture and history.
• This site has some interesting material on Japanese Family Crest / Ka-mon research.