Finding graphics on the WWW
Graphics can be easily downloaded from the WWW. However, images on the web are protected by copyright law and cannot be used unless written permission is given by the owner of the copyright, or the image is in the public domain. While images on the Internet are protected by copyright law, there are many sites that make images available for personal or educational use without a fee. There are also many stock photography sites that provide images for a fee. Make sure to read the copyright restrictions on these sites carefully. United States government web sites are a good place to look for images that are in the public domain and do not have copyright restriction against their use.
A Few places to Start Looking for Graphics on the WWW
American Memory Project
American Memory provides free and open access through the Internet to written and spoken words, sound recordings, still and moving images, prints, maps, and sheet music that document the American experience. However, this does not mean that the images are copyright free. Be sure to check the copyright and fair use guidelines. http://memory.loc.gov/learn/start/cpyrt/index.html
Copyright-friendly images for education
Source for Free Clip Art, Pictures and Illustrations
Limited permission is granted for use of up to twenty (20) images in total from the IconBAZAAR collections. Use of more than twenty (20) images requires a license.