General:
Websites for Kids
Islam:
Kids Zone Muslim Kids Site
Islam4Kids
Math:
Math Hunt
Math Brain
An Amusement Park of Interactive Math
Math Baseball
Science:
Yuckiest Websites
Volcanoes
Wonders of Science
Kids Planet
Animal Games
Discovery School
Language Arts:
Houghton Mifflin Kids Place
A famous Author Treasure Hunt on the Web
Social Studies:
Medieval Siege: Build a Virtual Trebuchet
Internet Treasure Hunt
Building Big: Construct Bridges, Domes, Skyscrapers, Dams & Tunnels
Inventure Place: National Inventors Hall of Fame