Multiple Media Types
“A database of 4,909,797 freely usable media files to which anyone can contribute.”
A database containing the text of over 30,000 (primarily public domain) books.
U.S. Government Photos and Images:
Most, but not all of these, will be public domain. So check the license terms for the particular site you are in.
The Library of Congress has a Flickr site and “[a]lthough the Library of Congress does not grant or deny permission to use photos, the Library knows of no copyright restrictions on the publication, distribution, or re-use of these photos. “:
1. CCmixter – Music
2. Freesound – Sound Effects
3. PDSound – Sound Effects
4. Sound Bible – Sound Effects
5. Public Domain Information Project – Music & Sheet music
7. ibeat – free beats, loops & breaks
8. Free Music Archive – Music