Communal Living in Russia: A Virtual Museum of Soviet Everyday Life
Wow, what a good website. It's got everything: a series of interviews (conducted in Russian, but with English transcripts available in each one), floorplans of communal apartments, essays about every topic from "How does privacy even work in one of those things?" to "How to you divide an electric bill of about $3 between 12 families?", a series of documents from said electric bill to a preemptive denouncement, and a list of books and suchlike for further study, in case that isn't enough for you.
This website contains a few complete translated works from the Soviet Era, several more summaries of works, biographies of several important Soviet authors, and some other related things, like Fandeev's suicide note, the music of Bulat Okudzhava, and various stuff about MetrOpol.
Babi Yar: A Document in the Form of a Novel
A first-hand account of the Babi Yar massacres, the Nazi occupation of Kiev, and beyond. Something unique to this book, as far as I can tell, is that it was written and published in stages, and the complete version has differentiated text so you can tell which was done when. The bolded text was cut out by Soviet censors, and the text in brackets was added after its initial publication, when the author was not writing with intent to publish.
Political Humor Under Stalin: An Anthology of Unofficial Jokes and Anecdotes
It's more or less what it says on the cover. Well more really: there are a lot of footnotes, to the point where a friend looked over my shoulder while I was reading it and thought I was reading a Discworld book at first. They're really useful for explaining jokes which require knowledge of who was in the Soviet government at the time they were told, or when the jokes rely, at least in part, on word play that translation can't quite get across. And then every so often there's one which reads something like "We can confirm that at least one woman was sent to gulag for recording this joke in her diary."
I cannot, for the life of me, find a Soviet tag, so I hope the Russian ones are correct.