Other
Nevada Seismological Laboratory: Plate Tectonics, the Cause of Earthquakes
This site contains an in-depth explanation of the causes of earthquakes as they relate to plate tectonics, and also has many nice and easy to read pictures, maps, and diagrams of plate tectonics and earthquakes.
Enchanted Learning
Enchanted Learning: All About Plate Tectonics
Simple discussion of plate tectonics and Pangaea. Includes maps and interactives.