(Sample link) White House for Kids http://www.whitehouse.gov/kids/whlife/index.html
(Sample link) National Geographic for Kids http://www.nationalgeographic.com/kids/
Math Fun http://www.hotmath.com
Math Forum http://www.mathforum.org/dr.math/
World Almanac for Kids http://www.worldalmanacforkids.com/explore/index.html
Create a Graph http://nces.ed.gov/NCESKids/grapging/