Atlas of the World
A comprehensive online world atlas which contains maps and geographic information for every country and U.S. state.
The Infoplease Atlas provides large, crisp basic maps of every country.
The Merriam-Webster maps provide nice detailed maps of every country.
Perry-Castañeda Library Map Collection
The Perry-Castañeda Library Map Collection is an extensive collection of scanned maps, many of which are very large and quite detailed. Scroll down to "Online Maps of General Interest" and select the continent and then country of interest.