If you happen to be traveling from one of the Baltic states, Finland or Sweden, then driving your own car to Russia may be a good option. There are many tourists traveling by car from these
countries, as well as a steady flow of second-hand cars imported to Russia from Germany. All this means that the customs regulations are quite straightforward and the infrastructure on the road
is good. However, this also means longer queues at some border crossing points.
If you decide to go through Belarus (remember that you need transit visa), keep E30 motorway which crosses Brest and Minsk (Belarus) and then passes through Smolensk in Russia and finishes in Moscow.
The shortest route from Poland to Russia avoiding Belarus (and thus transit visa hassle) is to travel through Kaunas (Lithuania), Riga (Latvia) entering Russia near Pskov.
The best is to enter Russia through the border with Latvia, Estonia or Finland, as all of them belong to same economic area (EU), which means less hassle.
If you are traveling from Finland, Nujimaa/Bruschnishnaya control point is usually quite fast, while Valimaa/Torfjanak usually has longer queues. The border between Latvia and Russia is usually not too busy, but it depends: sometimes you can get through the border in 20 minutes, sometimes you might have to wait 2 hours.
The petrol and diesel is easily available in Russia and there are generally 4 types on sale: 95 ("devyanosto pyaty" - that's what you use for most foreign cars - unleaded), 92 ("devyanosto vtoroi"), 80 or 76 (for old Russian cars), and diesel fuel. The 95 petrol is about 0.6 euro per liter, diesel is about 0.56 euro per liter, so it is about twice less than in Europe. There might sometimes be problems with the quality of the fuel, so it's better to use petrol stations that have some sort of brand name (BP, TNK, LukOIL are among the best ones).
Fire extingiusher and first-aid kit are mandatory.