Creative Commons Search
If you're looking for Creative Commons (CC) materials, the first resource to consult should be the search engine at creativecommons.org.
This search engine will mainly locate Creative Commons-licensed materials. It's not perfect since it will sometimes retrieve items that may not be covered by a CC license, and you should always verify the status of the work just to be sure.
With this in mind, it is still a good tool for getting started. The Creative Commons Search will search for web sites, images, videos, music tracks, and other online media that are covered by CC licenses by searching other search engines and tools like Google, Google Image Search, Yahoo, Flickr, Jamendo, Blip.tv, SpinXpress, and Wikimedia Commons. Enter your search terms and then select the tab for the kind of material you need.
Need CC pictures of cars? You can find such images through an index by car make as well as a search box.
This site provides access to some very interesting CC-licensed background images.
In addition to locating images through the Creative Commons Search, Google Images, and Flickr, this site provides access to tens of thousands of images that are free to use under a Creative Commons Public Domain license.
This site provides access to Creative Commons-licensed images with a travel theme.
Pictures of Animals: Animal Photos
Use this site to find CC-licensed animal pictures.
Prelinger Archives: Free Movies
This collection contains downloadable films that are covered under a Creative Commons 0 license (Public Domain). You can find, commercials, educational films, industrial films, some stock footage, and amateur films here.
Videos included in this collection are automatically assigned a Creative Commons Attribution/Non-Commercial/No Derivatives 2.5 license unless the filmaker decides otherwise. As always, it's a good idea to check the copyright or CC status of a work before you use it.
Many of the tracks available on this site are covered by CC licenses. This portion of the site allows you the ability to filter tracks according to different kinds of CC licenses.
Tracks in this site are covered by CC licenses. Search function may not be the greatest, but they have a large library of music to browse.
Free Sound Project
Need some sound effects? You may be able to download and use some from this site. Please be sure to carefully read the CC license accompanying each file to see what uses are permitted.
Disclaimer: This tutorial on using public domain materials, Creative Commons licensed materials, and copyright law is provided for informational purposes only! I am not a lawyer and cannot provide legal advice. None of what you read in this tutorial should be construed as legal advice. Should you require legal advice, please contact an attorney.