You Tube. Fun website. It has great material that can be used for classrooms. Many times when kids just don't "get it," you can find a clip that makes the lightbulb go off.
Two problems - it can't be accessed from school (for good reason) and it can't be trusted when we want to keep our kids safe.
Don't fret just yet - with a little planning, you'll still be able to access those YouTube videos that will assist in your instruction. This is where the video converters come into the picture, and there are several options out there. Depending on what works for you, you can use Video Converter, Media Convert, or Zamzar. I've tried them all, and the one I find that works the most consistently is Zamzar. With Zamzar, you can convert not only YouTube videos, but any file on your computer to almost any file type. Watch this for the easy steps: Using Zamzar to Save Videos.