The Free Music Archive: The FMA is a collection of high-quality, legal audio material curated by WFMU, a beloved freeform radio station in Jersey City, NJ. All material on the site contains a Creative Commons license so is available to use for free.
CCmixter: A community music remixing site featuring remixes and samples licensed under Creative Commons licenses. Over 38,000 (and growing) pieces of music are available.
Bandcamp: Music uploaded to Bandcamp with a Creative Commons license
Freesound: A collaborative database of audio snippets, samples, recordings, bleeps, and more.
Internet Archive: Audio: A massive collection of freely available audio material that ranges from the Grateful Dead to old time radio shows, news programming, poetry and more.
Opsound: Similar to Freesound, Opsound is a database of freely available music from hundreds of genres and artists started as a project of the artist Sal Randolph.
Public Domain Project: Thousands of audio, image, and video files in the public domain from the collection of the Pond5 stock footage company.
YouTube Audio Library: A collection of free downloadable music for use in video or audio projects.
Wikimedia Commons: Sounds: A database of 17,992,841 freely usable media files to which anyone can contribute"
World Hip Hop Beats: A collection of Creative Commons licensed hip hop beats.
TED Talks: TED is a nonprofit devoted to spreading ideas, usually in the form of short, powerful talks (18 minutes or less).
Vimeo: Hosts millions of Creative Commons-licensed videos. Filter to isolate them for browsing.
Khan Academy: Free online courses and lessons. Expert-created content and resources for every subject and level.