Terra Server - Find topographic maps and aerial photos.  Click on advanced find to locate your house or other place of interest.

UC Berkeley Topographic Maps - Check this site for a definition of topographic maps.  Also, topo maps from around the world like Mt. Everest, Mt. Kilimanjaro, Egypt, Vietnam, and more!  Also, hit this site for pictures of topo map symbols.

TopoZone - Just type in your town and state and TopoZone will locate the corresponding quadrangle!

USGS Topographic Maps - This site offers information on topographic maps as well as where they can be purchased.

TerraFly - Type your address and town or zip code and get in touch with a new way to navigate the digital earth.

USGS Topographic Map Symbols - This site offers pictures and explanations of all topographic map symbols as well as other interesting information on topographic maps!