ClipArt Sound Sources
us.audionetwork.com
freemusicarchive.org [free]
bensound.com [free]
Moby's music for non-profit use [free]
FreePlayMusic.com
soundsnap.com [pay site]
freesound.org
archvie.org
jamendo.com [great source]
creativecommons.org [music and photos source]
Prelinger [video source]