http://www.911forkids.com/ 9-1-1 For Kids – A children’s educational program.
http://www.fbi.gov/fbikids.htm A kids site from the Federal Bureau of Investigation.
http://www.atf.gov/kids/index.htm A kids site from the Bureau of Alcohol, Tobacco and Firearms.
http://www.kids.gov/ The Official Kids portal for the United States Government.
http://www.fema.gov/kids/ FEMA for Kids.  Federal Emergency Management Agency.
www.whitehouse.gov/kids Whitehouse Kids Page.
www.epa.gov/kids Environmental Kids Club from the United States Environmental  Protection Agency.
http://epa.gov/climatechange/kids/index.html United States Environmental  Protection Agency – Climate Change Kids Site
http://bensguide.gpo.gov/ Ben’s Guide to U. S. Government for Kids.
http://www.va.gov/kids/ VA Kids from the Department of Veteran Affairs.
http://www.ars.usda.gov/is/kids/ Science for Kids from the United States Department of Agriculture.
http://www.mypyramid.gov/kids/index.html Food pyramid site from the United States Department of Agriculture
http://www.niehs.nih.gov/kids/ National Institute of Environmental Health Sciences kids pages.
http://www.usfa.dhs.gov/kids/flash.shtm United States Fire Administration for Kids
http://www.loc.gov/families/ Library of Congress for kids and families.
There are many, many more sites on the internet for kids and families.  You can search at http://www.usa.gov/ for other sites.