How to Get to The Mariinsky: Accommodation and Traveling

Sleeping.
As far as I know, there are not many hotels near the Mariinsky because most of the tourists want to stay closer to Admiralteskaya or Nevsky Prospekt. The Mariinsky is not exactly main-interest downtown even though it is one of the top touristic attractions. P.Z.’s advice might vary provided the objectives of every reader. Nevertheless, assuming the readers are tourists, P.Z. would advise them to choose their hotel independently from the location of the opera house. In most of the cases, taking a taxi to the Mariinsky would be the wisest choice. So just choose your hotel according to your budget and main touristic attractions and get a taxi to the Mariinsky. Learn more about this on How to Get to The Mariinsky: Transportation.  

What To Do in St Petersburg?
There are so many more things to see other than the opera in St Petersburg. You will be missing out on the trip if you don’t see the Neva and its façades at night, the bridges when they’re open, the Cathedral of the Savior on The Spilled Blood, the Fortress, Peterhoff—just to name a few of the beautiful attractions. There are also lots of other things to do in St P; just buy a touristic prospect and it will most likely have everything you need to know. Don’t go just because of the opera because you will be amazed by the architecture—unfortunately most probably not by the performances. Two of classics at both the old Mariinsky and the Mikhailovsky are Eugene Onegin and Swan Lake and are must-see repertoire. More information will be available on my How To Choose Your Operas post.

When to Travel to St Petersburg?
Paradoxically, I would say that the best time to be in St Petersburg is precisely in August when the Mariinsky is closed. At least if you want to find good weather. St P is a problem during snow time because the snow is very dirty downtown and the cleaning service is not sufficient. I would say that the best time to travel to St Petersburg if you want to catch some opera or ballet is either just before the Mariinsky closes or after it re-opens. I would prefer the first because you can still catch the famous White Nights. In you are in specifically for the opera, the best performances will typically take place December-January because many of the great international Russian singers will be back for holidays. More info on How To Choose Your Operas.
Don’t forget that every non-Russian citizen needs a visa to pass the border. I have heard of many people (especially Italians) who had serious problems having their visas issued; make sure you have a visa by the time you start booking hotels and buying tickets. Getting a visa is an absolute nightmare of bureaucracy that can take require weeks to solve, so you might want to call up your local Russian visa centre before actually going there. On the other hand, a travel agency will most likely take care of your visa for a fee.

Getting Cash. 
The Russian word for ATM is bankomat. As far as the Mariinsky is concerned, as of January 2015, there is one ATM at the entrance of the old Mariinsky. There is no ATM at the Mariinsky-2 and the bars of both opera houses do no not accept credit card.