Don't let Americans beat you to it.
This is the largest and most recently (click here) acquired collection of Soviet documents at Harvard. It consists of materials microfilmed in Russian central archives since 1992. Most of the microfilm is of finding aids (opisi) for three of the most important Moscow archives -- the Center for Storage of Modern Documentation (TsKhSD), the Russian State Archive of Social and Political History (RGASPI), and the State Archive of the Russian Federation (GARF). These finding aids will be of tremendous use to anyone planning a research trip to Moscow.
This web site, however, will deal only with actual documents (as opposed to finding aids) microfilmed for the collection and present at Harvard as of the summer of 2002 (microfilming continues and new documents are still arriving). Modern Russian archives are generally organized as follows....