A few links to help you find creative commons-licensed images. Do not automatically assume that every image you find via these links is CC-licensed or in the public domain, however. Always double-check usage rights. The clause is usually fairly easy to spot.
Umbrella search sites. I’d start with these if I were you.
- http://photopin.com (Be careful of resolution issues!)
These are more focused links.
- http://deathtothestockphoto.com (You’ll need to sign up for the newsletter.)
- https://unsplash.com (Sign up for the newsletter and they give you the week’s new photos. There is a “download all” link from the email newsletter.)
- Wired goes CC with their images! (Wired.com Goes CC!)
Or you can try a modified Google image search.
Use Google’s “Search tools” menu to modify the “Usage rights” from the default “Not filtered by license” to “Labeled for reuse.” Do not, however, forget to check usage rights per image to avoid misuse. (You’re welcome for the adorable but totally gratuitous puppy photos.)