NeoK12

http://www.neok12.com/

This is AWESOME! When looking for videos, I typically have looked to www.unitedstreaming.com which is part of Discovery Education. I probably would still check there but this is an excellent bonus resource. The reason I like this website is twofold. First, all subjects are outlined on the homepage. Second, all videos are categorized by grade level and reviewed by teachers.

Math Wire

http://www.mathwire.com/

I can't wait to use this site. It's activities and games organized by content standards. Tons of pdf files free for download.