EduTechieGal has unearthed another web gem over at her site. NeoK12 is a site which has compiled and categorized (thank you!) hundreds of educational videos for grades K-12. The site is labeled as 100% Kid Safe, as all video submission are reviewed and approved prior to posting. Definitely worth a look! You can also help build that site into a more valuable resource by referring videos which you presently use or have created yourself.
And if you still haven't checked out EduTechieGal, she's got over one hundred tools for teaching posted on her site. She gives you just enough of a riff to explain it, and the rest is up to you.