Many geographical publications, data and maps are available at the following websites:
CIA World Factbook
Provides information on the history, people, government, economy, geography, communications, transportation, military, and transnational issues for 267 world entities.
DataFinder - U.S. Population Reference Bureau
Information about population, health, and the environment.
National Map Project
An online, interactive map service that provides public access to high quality geospatial data. From the U.S. Geological Survey.
U.S. Census Bureau
Conducts data collection about the U.S. population. Demographic data on language, geography, and social and economic characteristics.
U.S. Geological Survey
Provides information about natural hazards, water, energy, minerals, and other natural resources; Also ecosystems and the environment, and the impacts of climate and land-use change.