This collection includes printable outline maps of the world, continents, regions, countries, the states of the U.S., and the provinces of Canada. Maps are free "for educational or personal use at home or in the classroom."
Google Earth combines the power of Google Search with satellite imagery, maps, terrain and 3D buildings to put the world's geographic information at your fingertips.
The 1999 National Geographic Atlas of the World recognizes 191 independent nations. All of these, plus U.S. states and Canadian provinces, are available at this site. In each entry you'll find key geographic, demographic, and economic data as well as a brief overview.
"The Microsoft Research Maps Web site is one of the world's largest online databases, providing free public access to a vast data store of maps and aerial photographs of the United States. Microsoft Research Maps is designed to work with commonly available computer systems and Web browsers over slow speed communications links."
This site uses digitized aerial photographs from the United States Geological Survey and high-resolution satellite images from Russian mapping satellites.