White House for Kids http://www.whitehouse.gov/kids/whlife/index.html
National Geographic for Kids http://www.nationalgeographic.com/kids/
Starfall http://www.starfall.com
Awesome online activities for all ages http://www.funbrain.com
The site of NASA's K12 internet iniative. Here you will find useful teaching material, opportunitites to meet and interact with NASA scientists and useful support for students and teachers! Awesome! http://quest.arc.nasa.gov/
Site includes a variety of coloring projects, stories, games and online atrwork by children. http://www.crayola.com/
Noggin...using your brain! http://www.noggin.com
PBS Kids http://www.pbskids.org