The Avalon Project: World War II Documents – Yale Law School – A variety of primary-source documents on World War II.
Digital Public Library - "DPLA offers a single point of access to millions of items from libraries, archives, and museums around the United States." The DPLA portal allows you to search digital collections from institutions and organizations such as Hathi Trust, Internet Archive, the Smithsonian, the National Archives, Boston Public Library and more.
The Doctors Trial – – United States Holocaust Memorial Museum – Excerpts from the trial at Nuremberg, Germany of the Nazi physicians accused of war crimes against concentration camp prisoners.
HathiTrust - HathiTrust is a partnership of academic libraries and research institutions that have come together to build and share a digital repository of print works. The HathiTrust Digital Library has "more than 10 million volumes, making it one of the largest research library collections in the world. Over 3 miillion of these volumes are in the public domain and fully viewable online."
Internet Archive - The Internet Archive hosts one of the largest collections of freely available digital content on the Web and includes digitized print books, audio files, moving images and, by means of the Wayback Machine, cached copies of websites.
Women Who Came to the Front – Library of Congress – An exhibit featuring the work of eight women who participated as journalists, broadcasters, and photographers during World War II.
World War II Posters: Powers of Persuasion – National Archives – An exhibit that displays and explains ten World War II propaganda posters. Additional World War II posters can be found in the World War II Poster Collection at the Northwestern University Library.