St. Petersburg metro system has 4 lines and 57 stations.This is the most convenient form of public transport in Saint Petersburg and one of the safest metro systems in the world. Trains run from 5.30 - 6.00 in the morning to midnight and are kept under constant surveillance by the police force.
It is easy to use the St. Petersburg metro system even though there are no signs in English inside the metro stations. As you can see on the St Petersburg metro map, every line has its own color. Metro entrances are marked with a large letter "M".
Orientation. There are metro schemes (in Russian) in every car.
Tickets. St Petersburg metro has no special zones - the entire metro is one zone. And there's no time limit for using your token (ticket). So you can buy a token (ticket) for 17 rubles for one trip ($0.72 or 0.46 EUR) and spend as much time inside as you need.

St Petersburg Metro Map