CIA's World Factbook

CIA's World Factbook provides information on the history, people, government, economy, geography, communications, transportation, military, and transnational issues for 266 world entities.
The Reference tab includes: maps of the major world regions, as well as Flags of the World, a Profile Guide to Countries, a Physical Map of the World, a Political Map of the World, and a Standard Time Zones of the World map... There is also a Kid's Page with games.
A good way to learn about geography and politics!