National Geographic for Kids http://www.nationalgeographic.com/kids/
educational games http://www.funbrain.com
calendar, alphabet, reading, and other learning activities http://www.starfall.com
writing practice http://www.handwritingforkids.com
variety of learning activites (some are free) http://www.enchantedlearning.com
educational games (rhyme, alphabet, letter sounds, opposites, and others) GO TO GAME GOO http://www.earobics.com
assorted games for learning http://www.learningplanet.com
activities in different subjects http://www.iknowthat.com