Check out these sites with free teacher resources to spice up teaching and learning opportunities!

Academic Earth
Online courses from the world's top scholars. Allows you to grade the professor and create playlists around themes.

Empowers educators to deliver and share curricula. Helps connect parents, educators and students in the development of curricula and other educational materials.

Free (Free Resources for Educational Excellence)
Teaching and learning resources from federal agencies.You can add the RSS feed to your RSS reader.

iTunes University
Everything you need to create and share complete courses all in one place.

Library of Congress for Teachers
Classroom materials and professional development to help teachers use primary sources from the Library's vast digital collections in their teachings.

Microsoft in Education
K-12 classroom resources such as lesson plans, teaching guides, product how-tos, templates, free software, teacher community and more.

Microsoft Partners in Learning
Tutorials, free tools and a global teacher community.

NASA for Educators
Provides articles and helps teachers find resources that can be used in the classroom.

The National Science Digital Library
The nation's online library for science, technology, engineering and mathematics.

PBS Teachers
Online professional development, TV programming and multimedia web content, lesson plan ideas and ways to connect with other educators.

Teachers' Domain
Digital media for the classroom and professional development.

Provides free and easy to use resources to teachers dedicated to improving the education of today's generation of students.

Free digital learning platform from the Verizon Foundation that offers comprehensive teaching and learning resources created by content partners.

And here are a few more!

Facing the Future
Critical Thinking, Global Perspective, Informed Resources. Curriculum, sustainable resources, professional development.

HP Teacher Experience Exchange
Lesson plans, discussions, professional development, and web tools.

Integrated Academics Wiki
Place for teachers to share ideas about applying academic content across the curriculum.

Free tools and resources for teachers.

ITVS for Educators
Videos, lesson plans and community classroom for grades 9 - 12.

SAS Curriculum Pathways
Interactive standards based resources for grades 6-12 in English language arts, science, social studies, mathematics and Spanish.

Technology, Education & Design - videos.

<Free education videos organized by subject.

Zane Education
Visual learning, subtitled videos, quizzes, study tools lesson plans. Does not use YouTube to upload videos.