Amazon. When Titans Clashed: How the Red Army Stopped Hitler by David M. Glantz, Jonathan M. House. Also available in hardcover.
Reviewed by David Grier, on H-German (1996).
Amazon. Barbarossa: The Russian-German Conflict, 19411945 by Alan Clark.
The Road to Victory 1941-1945 from the Voice of Russia (State Radio). This is the Great Patriotic War from the Soviet perspective, largely if not entirely compiled from Soviet sources.
World War II
BBC History: World War Two. Excellent, deep site, with an emphasis on popular participation.