Ben's Guide- A great place to learn about the U.S. Government.
Lexile- Type in student's reading range and you will get a list of books in that range.
Math Fact Cafe- Assorted free math worksheets, includes time, money, and word problems.
RHL Schools- Free worksheets covering reading inference, reading comprehension, basic English, math problem solving and computation, as well as research skills.
Scholastic for Teachers- Lesson plans, strategies, tools, free mini-books. and free programs and give-a-ways. Also features a Teacher Community to share ideas.