This website provides tons of information about the geologic and geographic processes that have shaped the world to the present day.  There are several lessons that students can click through as well as games and songs that reinforce the information presented.  Through this website, students can also access other websites on the KidsKnow domain, such as astronomy, biology, paleontology, history, math, and much more.

Website: http://www.kidsgeo.com/
Subject: Geography and Geology
Grade Level: 3-8
Price: Free