K-12 Science Lesson Plans - now includes other topics
TurfMutt for K-5 - Inspire your students to become environmental stewards! TurfMutt offers standards-aligned science lesson plans, educational videos, activities, puzzles and more for grades K-5 to promote your students' appreciation of the green space that surrounds them every day.
Nasa Core - a division of Spacelink
http://www.middleschoolchemistry.com/ - online chemistry curriculum