PBS Kids - http://pbskids.org/

Story Place - http://storyplace.org

Fun Brain - http://www.funbrain.com

Know It All - http://knowitall.org

Explore Learning - http://www.explorelearning.com

RAZ Kids - http://www.raz-kids.com/

Eduplace - http://eduplace.com/kids

Book Adventure - http://www.bookadventure.com