This is a great site with math and logic puzzles for grades 1 through 12. The emphasis is on understanding and applying concepts rather than memorizing facts.
A nice informational site where you can "see the world through children's eyes." Includes maps, g
Free art lessons for elementary ages.
Online reading, math, and spelling curriculum for elementary ages.
Complete math curriculum for jr. high and high school levels.
This subscription site has loads of resources for learning through children's literature.
A website with lesson plans, worksheets, labs, and activities on biology topics.