Library DIY

Herron Art Library maintains a list of image databases as well as information about citing images and copyright information.

Flickr's Creative Commons portal.

While not all images on Google Images are Creative Commons licensed, it is possible to limit your search results to only images available under a Creative Commons license. To do so, run your search in the standard Google Image search bar and then on the results page, click on search tools just below the search box. A further drop down menu will then appear with usage rights as one of the options. From there, users can limit results to the proper rights. Unfortunately, they do not use the exact language of Creative Commons licenses, but you can nevertheless use the service to find usable images.

A site that provides free, public domain images that don't even require attribution. Unfortunately, it also offers Shutterstock images, which aren't free, but they are clearly set off so I don't think users will find that too confusing. The search feature is particularly nice, supporting Boolean connectors and also the ability to search by predominant color of the image.

NASA's website offers access to many of their images, audio files, videos and other media, which are generally not copyrighted and freely available for use.

As government images, almost all of the images in this collection are in the public domain, though the website states that you must credit NOAA if you use one of their images. They especially encourage educational use.

The United States Department of Agriculture maintains a database of images pertaining to their work and areas of purview. Because the images were mostly taken for the government, virtually all are in the public domain. Any images that are not in the public domain are marked as such.

This site offers fully searchable access to media, including images, sounds and videos, that has been uploaded by users, mostly for use on Wikipedia. Most of the content is available under some sort of Creative Commons license and licensing information is clearly provided at the bottom of each piece of media's individual page.