Getty Search Gateway http://search.getty.edu/gateway/landing Search across Getty repositories, including collections databases, library catalogs, and collection inventories to locate books, periodicals, photos, and more.
ManyBooks.net http://manybooks.net/ 29,000 free eBooks available for Kindle, Nook, iPad, and most other eReaders.
Merlot http://merlot.org/merlot/index.htm A free and open peer reviewed collection of online teaching and learning materials and faculty-developed services contributed and used by an international education community.
The Internet Archive — Prelinger Archives https://archive.org/details/prelinger A collection of advertising, educational, industrial, and amateur films
National Gallery of Art https://images.nga.gov/en/page/openaccess.html The NGA has an open access policy for digital images of works of art believed to be in the public domain. Images are free of charge for any use, and users do not need seek permission. Images are available images.nga.gov.
National Gallery of Art https://images.nga.gov/ This site provides 25,000 free and re-usable images of art, each accompanied by a snippet of information on the original artist.
Getty Open Content Program http://www.getty.edu/about/opencontent.html The Getty makes available to be used for any purpose, without charge or permission required, all available digital images to which the Getty holds the rights or that are in the public domain.
Wellcome Images Library http://wellcomeimages.org/ Over 100,000 high resolution historical images including manuscripts, paintings, etchings, early photography, and advertisements are freely available& under the Creative Commons Attribution (CC-BY) licence, with an acknowledgement of the original source.
Harvard Law School: Finding Public Domain and Creative Commons Images http://guides.library.harvard.edu/finding_images This guide will help you find and correctly attribute public domain and Creative Commons images.
Free Digital Photos.Net http://www.freedigitalphotos.net/ Download free and premium stock photos and illustrations produced by our community of professional stock photographers and digital illustrators.
MorgueFile http://morguefile.com/license/morguefile Free photos you're free to adapt, use for commercial purposes, without attribution, under the following conditions: You cannot sell, license, sublicense, rent, transfer or distribute this image exactly as it is without alteration, and you may not claim ownership of this image in its original state, or you can receive permission to use from the owner.