White House for Kids http://www.whitehouse.gov/kids/whlife/index.html
National Geographic for Kids http://www.nationalgeographic.com/kids/
Kids Gov http://www.kids.gov
Yahooligans-kid friendly search engine http://www.yahooligans.com
Kids Click! http://www.kidsclick.org
How Stuff Works howstuffworks.com
Discovery Channel School http://www.school.discovery.com
Cool Math 4 Kids http://www.coolmath4kids.com
Free Rice-for every word you define correctly, the United Nations donates 20 grains of rice! http://www.freerice.org