Education City http://www.educationcity.com
National Geographic for Kids http://www.nationalgeographic.com/kids/
White House for Kids http://www.whitehouse.gov/kids/whlife/index.html
Discovery Kids http://kids.discovery.com/
PBS Kids http://pbskids.org/
Play math games and create your own worksheets. http://www.mathplayground.com/
Math and reading games http://www.funbrain.com/
Scholastic http://scholastic.com
Time for Kids http://www.timeforkids.com/TFK/
Brain Pop Jr. http://www.brainpopjr.com/