Basic maps of most of Russia

Those maps of Russia are quite good and available for the Oziexplorer (all of them) as well as for Mapsource (only some of them). The site is russian, but google translate is a good helper there. The maps for the Garmin GPS can be downloaded as single .img files (right klick on the file, and klick save as). After that you can send them directly to your Garmin GPS device. If you don't know how to uploap maps directly to your GPS check Tips 'n Tools.