NASA for middle-school students http://www.nasa.gov/audience/forstudents/5-8/features/index.html
National Geographic for Kids http://www.nationalgeographic.com/kids/
Algebra Assistance http://www.algebra-online.com/
Purple Math (a great math/algebra resource) http://www.purplemath.com/
Author Project http://www.warrenlocal.k12.oh.us/whs/hsprojects/AuthorStudy/AuthorStudy.htm