Here is a great video showing a little bit about what iTunes U can offer. This video is older though, so realize there has been so much growth since then. Downloading content from iTunes means not having to stream it from the internet. It's permanently on your device!
iTunes U contains content from universities, schools, independent consultants, etc. TEA has their own page on iTunes U where they provide excellent content available for download. Here is some information about Texas Education on iTunes U.
We are also hosted on TEA's iTunes U page. You can find us by searching "Amoeba Sisters" in the iTunes store search bar.