So after yet another viewing of The Third Man, I want to know more about the place and the time, specifically what life was like there on a day to day basis. Google hasn't helped much, are there any books about the period generally, maybe something featuring a lot of diaries or letters, that sort of thing? I want to understand the place culturally, like what the different social groups were.
Thanks reddit!
/u/kieslowskifan might have more to add when it comes to English language scholarship but the fact is that the Soviet occupation of Austria (like the British or French occupation of Austria really) has not been that well explored so far by German language scholarship, to say nothing of English language scholarship. The reason behind this is that is has only been possible since the 1990s and really possible since the early 2000s to gain access to Russian archives of Soviet documentation of the occupation; access that is now waning again. This is also in contrast to Eastern German where the existence of the GDR has provided historians with documentation on Soviet activities in occupied while an "Eastern Austria" simply never existed.
All that said, the current standardwork on Allied occupied Austria and Vienna that is cited in German language scholarship is Manfried Rauchensteiner's Stalinplatz 4. Österreich unter alliierter Besatzung., Vienna 2005 which incorporates some of the newer research using Soviet archival documents. English-language wise you are probably best off with Rolf Steininger's Austria, Germany, and the Cold War: from the Anschluss to the State Treaty 1938–1955, 2008 or James Jay Carafano's Waltzing into the Cold War: the struggle for occupied Austria.. Personally I am more partial to Steininger for the reasons that unlike Carafano, who is a political scientist, Steininger tends to incorporate more the details you are looking for (e.g. culture) but be aware that the book is incredibly short (180 pages) and is used by people like me solely for its very useful bibliography.
Recent years have also seen a number of very interesting anthologies on the subject of especially the Soviet occupied zone in Austria, including large parts of Vienna and its surrounding areas. Among these is Ableiting et. al. Österreich unter Alliierter Besatzung 1945-1955, Vienna 1998; Karner/Stelzl-Marx: Die Rote Armee in Österreich. Sowjetische Besatzung 1945-1955, Beiträge Graz 2005; and the same authors publishing a volume of original documents on the same subject.
In English, your best bet for an anthology is Günther Bischof et. al. The Marshall Plan in Austria, 2000 and Steininger et. al. Austria in the Twentieth Century, 2009.
What I can further recommend, seeing as you got interested in the subject via the excellent film The Third Man is the book chapter on that film in Anne-Marie Scholz: From Fidelity to History: Film Adaptations as Cultural Events in the Twentieth Century, that stronlgy focuses on contemporary reaction to the film.
As a last word of warning, stay far, far away from Marcello La Speranza's book on occupied Vienna. Published by the Ares Verlag, the publishing house is known to focus very strongly on Nazi justification literature and it's selection of sources and narratives is not interested in presenting an actual history but a hit piece against the Allies justifying Nazi rule.