These are some practical resources which you might find useful for use in your classroom and for sharing with parents. The links are below.
Creative Commons Search Tool: This is the website for the Creative Commons organization. It includes detailed explanation of the different types of creative commons licenses as well as this tool for searching for media elements with creative commons licensing.
Flickr Creative Commons: Find high quality images with different creative commons licensing
CC Mixter: This is an online DJ community and a great source for finding music with Creative Commons licensing. DJs can share beats, loops, and vocal tracks and collaborate on this website
Internet Archive: This is a robust digital library that contains video, live music, audio, text, and much more. Many items uploaded to the Internet Archive are public domain. Make sure to check out the Prelinger archive for some great vintage videos, which can be remixed by students and teachers alike.