Photosforclass.com includes built-in #creativecommons search engine. Great search engine for free images that include image citations. Safe G Rated images.
Links to thousands of free audio clips that are copyright free. In digital storytelling, easy to drop these clips into Audacity or Garageband, etc. and create vodcasts of all kinds.
Search engine for images that have Creative Common licensing. It's always a good idea to educate yourself about the content you use. If you're unsure what Creative Commons is, or why copyright is important, take a few moments, find a few photos and and read the "License" information on the photo's page that comes up when you click "more info." The "more info" link is a great way to learn a little bit about the photograph, author, and various Creative Common's licenses, and what (if any) restrictions are applicable to that particular work.