The following selected web might prove useful to you. The sites are organized into groups by the general category to which they belong. As you visit any one of these sites, you will almost certainly find more links within the site that will take you out of the general category in which you first entered. (That is the nature of web links!) Also, it goes without saying that many more sites than these are available, and you will undoubtedly find others as you explore. Please let me know if you find a particularly good site that you think I should include. Also, please let me know of any listed sites that are no longer active (i.e., dead sites).

Minerals (start with the basics)

USGS basic mineral site covering the major rock forming mineral

WebMineral (very thorough)

Mineral Galleries (follow alpha links to mineral pages with lots of information)

Minerals in thin section (1) (more than you'll probably ever need to know about optical petrology, but it is very interesting)

Minerals in thin section (2) (100s of images of minerals and rocks -- all very well organized)

Rocks

USGS general primer on the three basic rock types and how they form

CUNY Brooklyn rock gallery (just images; run your cursor over the buttons to see them)

About.com (here and there some of the information might be a bit off, but the images are nice; explore the other galleries too)

Igneous, Metamorphic, & Sedimentary (lots of information about composition and origin of the three rock types, alpha listing link takes you to galleries)

Tours of Igneous, Sedimentary, and Metamorphic (thorough; the igneous tour is not as nice as the others and the authors get kind of silly at times)

General Geologic Concepts and Reference Sites

USGS site on Plate Tectonics (a good concept to know)

USGS publication on the information potential of fossils and rocks (perhaps a bit dated)

Online dictionary of geologic terms (unfortunately not searchable but this is the best one I have found)

Geologic Time

UC Berkeley Museum of Paleontology geologic time page (great, just follow the links)

Virtual Fossil Museum geologic history page (excellent site, follow the links)

Geological Society of America timescale (printable .pdf format available here)

USGS publication on geologic time (a bit dated now, but it still conveys some of the concepts quite well)

Earthquake and Seismic Hazard Sites

USGS Earthquake Hazards Program (click world or US maps to see recent earthquake data; click Learning & Education link for lots of information)

IRIS Seismic Monitor (global database of recent earthquakes)

OhioSeis (The Ohio Seismic Network)

Ohio Earthquake Hazards (information about Ohhio earthquakes and seismic risks)

USGS Northern CA Earthquake Hazards Program (much research into assessing earthquake risks and possible prediction is conducted in California)

Izmit, Turkey 358 AD, Lisbon, Portugal 1755, and Izmit (Kocaeli), Turkey 1999 (Two historic accounts of earthquakes and one modern analysis)