When you are travelling about in Russia it is a good idea to travel lite for a variety of reasons. For one, if you are riding the Russian rails, you don't want to be tossing around heavy baggage from the platform into and out of your train car. It isn't like America where there is barely any room between the train platform and getting into the train car. In Russia there can be a substantial distance between the edge of the platform and getting into the car. In places such as Kazansky Station in Moscow, not only is there are significant gap between the platform and the train car, you also need to make your way up a set of narrow, nearly vertical set of train steps into the car.
Last time I made the trip, I took 3 pairs of slacks, 3 shirts, 3 pairs of socks, 3 pairs of underwear, and a minimal amount of the necessary bathroom sundries for washing, shaving, oral care, deodorant, etc. I was going for 3 weeks, and simply washed the clothes I wore each day, and changed to another set for the next day. If you pack smart, you can get away with only a carry on. If you take more than one suitcase that you have to check at the airport, you will have to pay extra for the second suitcase, up to $100.00 or more US.
Make sure you also take a decent digital camera so you can document the places you've been and the people you've been with. If you aren't a professional photographer, don't go overboard and get some huge digital SLR that is going to bog you down. I've found that a
camera is small enough, light weight enough, and has enough options for it to be a good all around camera and it has pretty good resolution for a small digital camera.
Also, unless you are already a fluent speaker of Russian, take with you a small pocket Russian-English dictionary or a lightweight electronic translation machine.
Before you go, learn some basics, such has "hello, please, thank you, how much, and where's the bathroom." You should also learn how to use the toilet squatting instead of sitting, not that you'll have to do that everywhere, but there are places where it might be handy knowledge.
