I'm pretty sure what they mean is that when you get to where you are going, you need to register yourself in that city. Basically, what happens is whenever you get to your hotel, you give them your passport, and they hold it for (usually) a couple of hours. What they are doing is registering your passport with the government. I don't beleive there is any paperwork to fill out (other than the migration card which you usually get on the airplane when you are landing). I wouldn't worry about going to an OVIR office, the hotel will suffice. Just be sure to keep your plane ticket on you until you register, because sometimes police officers will ask for your registration. You are legally allowed to be in a city for 72 hours without registration, and your plane ticket can verify when you arrived.

If you do have questions when you arrive, and are staying at a hotel in a big city (Moscow, St. Pete), they usually have somebody on staff who speaks english, so I wouldn't worry too much.

hope this helps

tdk