KGBDocuments.eu offers decades of previously highly classified documents from the former KGB headquarters in Latvia, Estonia, and Lithuania. They are now available online - with more planned to be available soon - in Russian and English.
Inventory of Slavic, East European, and Eurasian Digital Projects has a name that says it all.
New York Public Library has one of the largest collections of Slavic primary documents in the US. See their image gallery.
Russian Satirical Journals Project makes USC's unique collection of Russian Satirical Journals produced during the revolutionary upheaval of 1905-1907 available on line, accompanied by a searchable database which offers detailed information on these rare periodicals, those who produced them, and their cultural and historical context.
Metropolitain Museum of Art Libraries has several digitized, rare Russian books.
Oldmos.ru and Oldsp.ru offer hundreds of old photos of Moscow and St. Petersburg. Set the sliders for the date range you want and the interactive map will show you only those pictures within that range.
Pobeda-kosmos.ru provides archival documents, photos, and video of the Soviet space program.
LiveJournal can be great resource for those who speak Russian an want to find out more about how today's (middle-class, well-educated) Russians live and how they feel about Soviet times.
Kotoroy.net provides histories and photographs of landmarks in Russia that are no more.
Savok and offers hundreds of high quality photos of the USSR wtih free access.
ColdWarFiles.org provides access to translated documents, many recently declassified, that pertain to the Cold War.
The Cold War International History Project is a contributor to ColdWarFiles.org and has many other documents available on its own site.
Stalinka is a scholarly-referenced collection of more than 500 images comprising representations of Stalin in various genres. This resource will be invaluable to anyone researching Stalin, the cult of personality that surrounded him, or Soviet propaganda.
The Duke Library Russian Posters Collection consists of 75 Russian posters, documenting almost 60 years of Communist political advertising.
The Harvard Project presents mostly interviews with Soviet refugees to the States - information on cultural, social, and economic conditions in the USSR in the early years of the Cold War.
Electronic Library of Russian Literature and Folklore is a very good resource for those subjects.
Folk.ru provides oral history and modern folklore from Russia.
The Ukrainian Folklore Project is an interesting site sponsored by the University of Alberta. Lots of info, pics, video footage and other multimedia presentations.
The Ukrainian Museum Archives offers lots of "online exhibits" of artifacts from Ukrainian culture and Ukrainian immigrant culture.
Gromoty.ru contains not only photographs, "prorisi" and translations of all published Novgorod birchbark letters, including recently excavated ones, but also historical, archaeological, bibliographic and linguistic comments on almost every one of them.
Obshezhitie.net is a site for those interested in early Russian manuscripts.
Anna.Ahmatova.Com offers biographical info on the poet and recordings of her reading her own poems.
RussianArchives.com offers many images, movies, and recordings - for a price.
Gulag: Many Days, Many Lives presents an in-depth look at life in the Gulag through original documentaries, documents and images, and teaching and bibliographic resources that encourage further study.
Berezka was a hard-currency store in the Soviet Union. It's 1975 catalogue is now online, showing what high-end food items would have cost at that time.
Color Code: Red links are to sites only in Russian.
Gray links have English available.
Gray links have English available.
Full list of online Russian resources here: http://www.sras.org/library_russian_archives