I became a big fan of Planet Nutshell the first time that I saw their series of videos on Internet Safety. They've also produced great videos on Financial Aid, Climate Science, Health, Mathematics, and Physics. This morning I was exploring the Planet Nutshell website and notice that all of the education videos are now available in one section of the site labeled Teacher Library.
NetSafe Episode 1: What is the Internet? (Grades K-3) from Planet Nutshell on Vimeo.