Turtles are still somewhat slow getting onto the web, but there are a few excellent pages with abundant information on our shelly reptilian friends. Try the first few links first; these are the most comprehensive pages and would be a good starting point. Enjoy!
The World-Wide-Web Virtual Library -- Herpetology
Other herpetological collection catalogs
Desert Tortoise Preserve Committee
California Turtle and Tortoise Club
The skildpadder information page (Turtle links galore!)
Turtle Trax -- marine turtle information
The National Turtle and Tortoise Society
Subclassis Anapsida: Ordo Chelonia
Sea Turtles - U..S. Fish and Wildlife Service
Endangered Species: Honu, the Hawaiian Sea Turtle
1995 Year of the Sea Turtle in the South Pacific
Herp Pix -- Turtles and Tortoises
Centro Mexicano de la Tortuga -- National Mexican Turtle Center
Turtles, tortoises and terrapins
Green turtles (and more) at Cal-poly