Step 1: Go to www.youtube.com
Step 2: Enter search terms in the search box at the top of the screen.
Step 3: On the results screen, click on Filters; choose Creative Commons.
Step 4: Click on the title of the video you are interested in. You should see a summary listed under the About menu. Click on Show More to verify the license type. (All Creative Commons-licensed videos are licensed as CC-BY, which means you must give attribution.)
NOTE: Do not automatically assume that the person who placed content on YouTube is the copyright holder or originator. You will need to verify its authenticity before using the video, even if it is licensed under a Creative Commons license. A good rule of thumb: if the person who placed the video on YouTube is not affiliated with the company or institution who clearly created it, it was likely posted illegally.
Under YouTube's Terms of Service, users are granted "a non-exclusive license to access your Content through the Service, and to use, reproduce, distribute, display and perform such Content as permitted through the functionality of the Service and under these Terms of Service." This allows you to embed YouTube videos on your Web site or in your class using the embed feature offered by YouTube. When in doubt, however, link to videos that are still copyrighted.