This website provides links to information on state geological surveys for the fifty U.S. states.
Geology.com
Includes maps and satellite images of areas of geologic interest, information on current events in geology, examinations of geologic phenomena, and other helpful geology-related information.
Mindat.org
Mindat.org is the world’s leading authority on minerals and their localities, deposits, and mines worldwide.
Paleomap Project
Includes illustrations of plate tectonic development as well as an earth history section exploring the development of mountain ranges and other geologic phenomena. The site also includes sections on climate history and animations of plate tectonics.
USGS Website
Great website for many aspect of geology including information on earthquakes, volcanoes, and more.
Additional Resources
We have an additional collection of resources over here for Geology that we couldn't fit on a single page.