Statistics

General

• Statistical Abstract of the United States: U.S. Census Bureau

Children

• ChildStats.gov: Official federal government statistics on children's data, links to federal reports,
  tables, and databases

Crime

• Bureau of Justice Statistics:  A federal source for statistics on crime and the criminal justice system from the U.S. Dept. of Justice
• FBI Uniform Crime Reports
• Federal Justice Statistics Resource Center
• National Archive of Criminal Justice

Economic

• Agricultural Statistics: Online version for reference from the National Agricultural Statistics Service
• Annual Report to Congress: From the Board of Governors of the Federal Reserve Board
• Budget of the United States Government Main Page
• Economic Indicators:  Prepared and published monthly for the Joint Economic Committee by the
  Council of Economic Advisors
• Federal Reserve Bulletin: Online periodical
• Statistics on the U.S. Economy: From the Bureau of Economic Analysis
• Survey of Current Business: Online periodical
• U.S. Economy at a Glance: From the Bureau of Labor Statistics

Education

• National Center of Education Statistics

Health

• Center for Disease Control
• OSHA: Occupational Safety and Health Organization - statistics on work-related injuries, etc.

International Data

• Global Statistics: United Nations Statistics Division
• Handbook of International Economic Statistics (2009):  Data for comparing the economic performance of major countries
• World Factbook (U.S. Central Intelligence Agency): Economic, population, and other statistics
• for 267 countries around the world

Labor

• Bureau of Labor Statistics: Labor and employment data as well as the consumer price index

Population

• CityTownInfo.com: Characterizes U.S. cities and towns by comparing their various attributes against other cities and towns in the country
• Lewis Mumford Center for Comparative Urban and Regional Research: "As a public service,
  the Mumford Center makes information available on specific metropolitan areas and their
  respective city and suburban portions." It includes information on segregation and ethnicity,
  school segregation, homeowners and renters, etc.
• U.S. Census Bureau: Subject index of statistics and other data available