Video Alerts function like Google Alerts, but they just let you know about new videos uploaded to YouTube. Just type in up to ten words, and you’ll be notified when new videos relating to those topics appear.
Obviously, most school districts block YouTube, so you might want to look at The Best Ways To Access Educational YouTube Videos At School.
In that list, I recommend Edublogs TV as the easiest place to upload YouTube videos to make them accessible at schools. I still think that’s the case, but it’s having some technical issues right now. Until those get sorted out, which I’m sure will be soon, you might want to look at a new site I learned about called Watch Know.