This is an overview of the different types of sea turtles.  http://escambia.ifas.ufl.edu/marine/types_of_sea_turtles.htm

Here is a site that gives quality information about each type of sea turtle. http://www.cccturtle.org/species.htm

On this page, an elementary school in Canada has collected together a bunch of great sea turtle sites.  Browse these sites to find useful information about sea turtles.  http://www.stemnet.nf.ca/CITE/st_general.htm

Here is Wikipedia's Sea Turtle page.  At the top of the article are blue links for the different subspecies of sea turtle, like the Green Sea Turtle, the Leatherback Turtle, or the Hawksbill Turtle.  http://en.wikipedia.org/wiki/Sea_turtles

National Geographic has a Animal A to Z Article on the following Sea Turtles: Green Sea Turtle, Hawksbill Sea Turtle, Kemp's Ridley Sea Turtle, Leatherback Sea Turtle, Loggerhead Sea Turtle, Olive Ridley Sea Turtle.  Click on the links above to find the articles.

Now the National Geographic for Kids website has these Sea Turtle articles: Leatherback Sea Turtle and Loggerhead Sea Turtle.  Click on the links above to find the articles.

Here is another National Geographic article all about Sea Turtles.  This one has to do with the trouble facing Sea Turtles today.  http://www.nationalgeographic.com/ngkids/9911/turtle/index.html

The World Wildlife Fund's (WWF) page about Sea (Marine) Turtles gives all sorts of useful information like their habitat, background, a physical description, and lots more. http://www.panda.org/about_wwf/what_we_do/species/about_species/species_factsheets/marine_turtles/index.cfm