Science Education Resources
http://science.house.gov/resources/science_education.htm          

National Science Digital Library Topical Collections
http://crs.nsdl.org/collection/

K-12 Concept Maps for Science Teachers
http://strandmaps.nsdl.org/

Library of 3-D Molecules for Chemical Education
http://jce.divched.org/JCEDLib/index.html

NASA has established a major resource for science teachers
http://education.nasa.gov/about/contacts/Educator_Resource_Center_Network.html

Gateway to 40,000 lesson plans for teachers
http://thegateway.org/

Over 500 resources to 18+ fields of science
http://wdcrobcolp01.ed.gov/cfapps/free/displaysubject.cfm?sid=8

Dozens of exemplary math programs and resources
http://wdcrobcolp01.ed.gov/cfapps/free/displaysubject.cfm?sid=6

Federal Agency Science Lesson Plans for Teachers & Students
selected by Congress (House Science Committee)
http://sciencedems.house.gov/resources/lessonplans.htm

Discussing evolution with middle school students:
http://nsdl.enc.org/epubs/science/science3/science.aspx

Teacher recommended list of Science education resources:
http://www2.nsta.org/sciencesites/

Guide for New Math Teachers:
http://my.nctm.org/eresources/

Curriculum guides on renewable energy by & for teachers:
http://www.nrel.gov/education/resource.html

Eisenhower National Clearinghouse for Mathematics and Science Education (curriculum by science teachers for science teachers):
http://www.enc.org/

What Works Clearinghouse (WWC): Teaching practices based on good Research:
http://www.whatworks.ed.gov/

Resources for helping teachers use the internet effectively:
http://www.internet4classrooms.com

A cyber-community for teachers, students and researchers of Science (includes a place for teachers to explore resources for science teaching via the Internet):
http://www.ncsu.edu/sciencejunction

Ocean Sciences Teacher Resource Center 
http://www.vims.edu/bridge/

Little Shop of Physics, Colorado State University's hands-on science outreach program
http://littleshop.physics.colostate.edu/

Mathematics page from Education World (teacher/educator oriented)
http://www.education-world.com/math/

Knowledge Base to help find presentable facts to save, start, or improve your school's music program
http://supportmusic.com/public/index.php

Math Teachers pages for Families
http://www.nctm.org/families/index.htm

Teacher's Domain, a multimedia digital library for K-12 teachers and students:
http://www.teachersdomain.org/

Center for Biology Education, provides links to dozens of undergraduate education resources:
http://www.wisc.edu/cels/