Copyright Friendly Images
Most images on the Internet are copyright-protected and can only be used under strict requirements. Those requirements include citing the source (always) and not altering the image (no changing of sizes, no cropping, etc.). If cropping and sizing of images will be required, then images with creative commons licensing are the ones to choose. These images have been submitted by their creators for use by those who wish to make modifications to the images. NOTE: Citing of the images is still required.
Below are some of the more common and popular sources for creative commons images.
COPYRIGHT-FRIENDLY PHOTO WEBSITES
http://etc.usf.edu/clippix/pictures/
http://www.flickr.com/creativecommons
http://www.public-domain-image.com/
http://www.freephotobank.org/main.php
http://images.google.com/advanced_image_search?hl=en – Change usage rights= labeled for reuse w/modification
Eduscapes - a source of free photos for students to illustrate projects
Copyrightfriendly - this source from Joyce Valenza, 21st Century Librarian Guru, lists dozens of sites for multimedia photos, clip art, audio, etc.