These websites offer everything from lesson planning ideas, to activities, to free books, DVDs, and products for the classroom.

21Things4Students
21Things4Teachers
Ayn Rand
Basecamp
Dinosaur Train
Howard Hughes Medical Institute
Lenovo
Microsoft
NEA
PhysicsQuest
Sesame Street Learning Resources
Simpletivity
Stossel in the Classroom
Switch Energy Project
ZooZingo