Eisenhower National Clearinghouse (ENC)
http://www.goenc.com
Lesson plans and activities for many science topics including
process skills for grades K-12.
The Flying Turtle
http://www.flyingturtle.org/
Illustrated site celebrates and explains the basic scientific principles that govern both nature and human technology. Includes lesson plans.
Mid-continent Research for Education and Learning (McREL)
http://www.mcrel.org/lesson-plans/science/index.asp
Links to sites that contain lesson plans for grades K-12.
National Science Teachers Association
http://www2.nsta.org/sciencesites/
Links to sites that contain lesson plans including the
American Teacher that includes 200,000 plans.
NIH Office of Science Education
http://science-education.nih.gov/
Life science education resources and lesson plans for students, teachers, and the general public.
SCORE - Schools of California Online Resources for Education
SCORE Science Lessons
http://scorescience.humboldt.k12.ca.us/
The official site of the Humboldt County of Education that
contains lesson plans tied to the California Science Standards.