Research Oriented Sites:

http://mondvor.narod.ru - "Mondvor" site - a complete reference on Soviet awards. In Russian, but you don't need to speak the language to view the pictures.
http://www.soviet-awards.com - an excellent site, dedicated to Soviet awards and history.
http://www.soviet-awards.com/forum - join the Forum!
http://www.soviet-screwbacks.com - this site contains unique information on Soviet screwback awards.
http://www.undertheredstar.com - a very thorough research on Soviet headgear.

For Sale Sites:

http://www.russianglory.com - Soviet and Russian Imperial awards and militaria
http://www.russian-awards.com - Russian Awards (Soviet orders, medals and groups)
http://www.warinpieces.com - War in Pieces - a site from Down Under
http://www.collectrussia.com - CollectRussia by Igor Moiseyev
http://www.russian-medals.net - Dmitry Markov Coins & Medals
http://wwmilitary.com - World War Military