The State of California has created a special "Kid's Corner" site with an index of "safe" websites our children can use to gather information or do research for their school work. I attended California Public Schools from K-12 and just reviewing some of the recommended websites was a sentimental journey through the assignments of my childhood. "California Missions" and "Exploring The Faultline" are just two examples of sites linked from the "Kid's Corner". Even today, when I'm on an airplane flying from San Jose to Los Angeles, there is one approach used that goes right over the tectonic violence of the San Andreas Fault and I get a real shiver just looking at the evidence of powerful plate shifts.
Here's the link!
One thing to note: when you click a link you will be leaving the "Kid's Corner" site. I'd prefer they would open a new window since I think that might be easier for kids to manage but as long as kids (and their teachers) remember to use the "back" arrow in their browser, it should be fine.