It would depend on your visit. If it is the first - I'll let you know how to use metro and etc, show you around main attractions (so you can decide what to visit then) and some places that travel guides won't tell you. Saint Petersburg has lovely yards, where during summer you can have a drink. If you are visiting the city during a cooler season we'll still walk around but definitely choose for drink cafes with good coffee, tea or mulled wine! :)
If your visit isn't the first we'll skip a part with sightseeing :)