Ohio Department of Education Practice Tests
Contains on-line practice tests to prepare for the Ohio Achievement Tests. There are tests for grade levels 3-8.
http://ohio3-8.success-ode-state-oh-us.info/PracticeTest/
Fact Monster
Learning Network's Fact Monster includes an almanac, atlas, dictionary, and encyclopedia.
http://www.factmonster.com/
Ask Dr. Math
A great resource to help you with your mathematics questions and homework!
http://mathforum.org/dr.math/
Fun Brain
Internet Learning Games is an award winning website for students in grades K-8.
http://www.funbrain.com/