Here's a few things to get you started. Search the internet for Zoom, Nature channel, Discovery Channel, Nasa, National Geographic Some of these have movies. I would also look for Computer CDs and DVDs at the library for learning history stuff for kids.

http://pbskids.org/dragonflytv/
http://www.oceanicresearch.org/education/wonders/lesson.html
http://www.rokenbok.com/
http://sodaplay.com/
http://www.globalwonders.com/
http://georgessecretkey.com/cosmos/
http://www.show.me.uk/parents/parents.html