Homework Help Sites
General
Answers.com - Great content from thousands of reputable publishers.
FactMonster - Reference information and games
Great Sites for Kids - from the American Library Association
Homework Help - from Multnomah County (Oregon) Library
Kids.gov - Information for kids and educators from the US Government
Writing Papers
Editing Marks Poster - this is more basic than the first one
Great Sites for Teachers to Know About
Kathy Schrock's Sites of the School Days