Free Puzzles
Features educational and recreational puzzles for teachers, students and parents. 1000 puzzles collected, including Geometry, Logic, Math, Misc, Weight and Moves categories. Every puzzle has an image, hint and solution.
http://www.freepuzzles.com/

Puzzles.com
The world's best resource for puzzling on the Internet. Offers information about puzzles, illusions, tricks, toys, and everything around all these great funny, entertaining, intellectual and educational things.
http://www.puzzles.com/