I've recently come across a very useful website for exploring geology and paleontology. It's called The Paleontology Portal.
By far the coolest feature are their interactive maps. While currently limited to North America, they are a great resource. You can do things like:
- See how old the rocks in a particular region are,
- Check out what kinds of fossils are common in your area,
- View a very comprehensive gallery of fossils from all eras,
- and more.
The website also has great reference links to all aspects of paleontology, resources for K-12 educators, and listing of great museums and other facilities to learn more about the ancient past.