U.S. Geological Survey (USGS)

USGS Geographic Names Information System (GNIS)

USGS Global Land Information System (GLIS)

USGS MapFinder

USGS National Earthquake Information Center

Seismicity of the United States

USGS National Mapping Information

USGS Publications (Search)

STATE GOVERNMENT

Georgia Professional Geologist: State Board of Registration

Georgia Registered Geologist's List

Georgia Department of Natural Resources

UNIVERSITIES

ORGANIZATIONS

American Institute of Professional Geologists (AIPG)
 

Association of Engineering Geologists (AEG)

Geo-Institute of the ASCE

Karst Waters Institute

National Ground Water Association

OTHER SERVICES

Hydrogeologist's Home Page (links to hundreds of hydrogeological resources)

TerraServer (topo maps & satellite photos)

TopoZone (free online topo maps!)

About.com's 'Earth' Page (very comprehensive site featuring many articles and images relating to our fair planet)

MSNBC's 'Mysteries of the Universe' Page (a broad range of science articles, including geology, astronomy, health, etc)

Spacescience.com (mainly Space, but also has articles about interesting phenomena on Earth)