http://www.sitesforparents.com/ Hundreds of educational websites listed by popularity.
http://www.funbrain.com/ Over 100 free interactive math and reading games as well as online books created for students in preschool through 8th grade.
http://www.learninggamesforkids.com/ Elementary educational games that build skills in math, language, science, social studies & more.
http://www.readwritethink.org/ Reading and language arts resource to help parents make the most of time out of school for their children K-12.
http://www.mathplayground.com/ Action-packed site for K-8 students to practice their math skills or play a logic game.
http://www.sheppardsoftware.com Hundreds of educational games, activities and quizzes for ages preschool-8th grade in math, language arts, science, and geography.
http://www.starfall.com Systematic phonics and phonemic awareness activities for preschool-2nd graders.