1. From airport to metro

The bus #13 station is right near airport exit. Tickets are selling right in a bus and have a cost of 21 roubles. You go by bus about 15 min  to metro station «Moskovskaya»

2. Metro

After buying coins (25 roubles; you can use coin-selling automates or cashier) and getting in, you must go to station «Tekhnologicheskiy Institut», this is crossing staiton.
At this station you must get out from a train and go to an opposite side of platform.

After this you need to get in a train, and go to «Ploshchad’ Lenina» station and then follow the map

If you have any troubles call me +7 905 206 58 76

I not recommend to use a taxi, because of extremely non-humanistic prices, especially in airport. But if it is not a problem for you — please welcome to beautiful and comfortable St-Petersburgs taxi