General Reference:

• FactMonster
• Windows to the Universe
• Info Please

Encyclopedias

• Encyclopedia Britannica
• Columbia Encyclopedia

Dictionaries

• Merriam Webster

Almanacs

• CIA World Factbook
• Farmer's Almanac 

Art

• Met Museum Kids
• National Gallery of Art: Kids
• MoMA Kids
• Getty Games

Science

• How Products Are Made
• How Stuff Works
• NASA
• National Geographic Kids
• Weather
• Science Fair Resources

Math

• Practice Math Worksheets
• Dr. Math
• Cool Math
• Math is Fun

 
Social Studies

• Ben's Guide to the Government for Kids 
• Congress
• American Presidents
• 50 States

Language Arts

• Wacky Web Tales
• Spell Check Game

Foreign Language and ELL Resources

• Google Translate
• Babel Fish Translator
• BBC Language Learners
• Language.com
• Repeat After Us
• Learning Vocabulary Can Be Fun 
• Mrs. Hurley's ESL Page
• Windows to the Universe:
  • English version: http://www.windows.ucar.edu     
  • Spanish version: http://www.windows.ucar.edu/spanish
    

Computers 

• Basic HTML for Kids
• Coding for Kids