Getting into Russia is easy if you are on a cruise or organized group. If you go ashore with an organized shore excursion, or a licensed guide, you need only carry your passport. It does not have to be an excursion sponsored by the ship, but you will need to get the paperwork in advance via email from any local guide you use for touring. (The cruise ship will return your passport for the duration of your St. Petersburg stay and reclaim it before you sail.)
However, if you want to do independent touring of St. Petersburg, you will need a Visa. Getting your Russian Visa isn't difficult, but can take several weeks of pre-cruise planning. If you know that you want to tour on your own, check with your travel agent or cruise line to arrange for a Visa. This cannot be done after you sail!
I have been to St. Petersburg three times. The first two times I toured with the ship or an independent guide, Alla Ushakova, and did not obtain a Visa. When we exited or re-entered the ship, Russian Customs Officers on the pier checked our passports thoroughly. We were amused that a New Orleans-style jazz band entertained us while we stood in the customs line, but it made the time (about 10 minutes) go by faster. When I needed a Visa for our Russian Waterways cruise tour with Grand Circle Small Ship Cruises, I was happy to be able to tour on my own. The city is very easy and interesting to tour on your own, and staying in a hotel near the city center was a wonderful treat.
St. Petersburg Weather
St. Petersburg's weather can be brutal in the winter, but summer brings temperatures into the 70's and 80's. Since the city is located on about the same latitude as Oslo, Stockholm, and Helsinki, it has wonderfully long daylight hours from May to September. It's also as far north as Alaska! I have cruised to St. Petersburg in both July and August, and had glorious sunny days. However, our guides told us that we were extremely lucky, since often the weather is cloudy and gloomy, even in the summer.
St. Petersburg Currency
The Russian Ruble (RUB) is the local currency. Banks and exchange offices are open Monday through Friday from 9:30 am to 5:30 pm for those wishing to exchange currency. Major credit cards are widely accepted, and ATMs are increasingly common. The souvenir shops accept dollars, as did all of the street vendors. However, restaurants and other shops require the use of rubles. We used a credit card for larger purchases.
St. Petersburg Language
Russian is the official language of St. Petersburg, but English is widely spoken. The Russian language uses the Cyrillic alphabet, but many signs in tourist areas feature both Russian and English.
St. Petersburg Shopping
Most stores are open Monday through Saturday from 9:00 am to 5:00 pm, and stores along Nevsky Prospect, a main shopping street, may stay open until about 8:00 pm. The cruise ship pier we docked at has numerous souvenir shops, and even some with jewelry and handicrafts. (Some small cruise ships can sail further up the Neva River and dock at another pier - be sure that if you tour independently that you know where your ship is docked!) Shopping kiosks are found throughout the city, with a large market across the street from the Church on the Spilled Blood. Some kiosks are reportedly Mafia-operated, but we felt goods were fairly marked and did not hear any shopping "horror" stories from any of our shipmates. Pickpockets do frequent the tourist areas, so watch your bags and cameras. Street vendors are plentiful at all tourist sites. The price for books and souvenirs is MUCH better when you are boarding the tour bus to leave a site than it is when you first arrive!
St. Petersburg Must-See Sites
Most cruise ships spend two days or three days in St. Petersburg, but that's still not nearly enough time to see everything. An organized ship's tour or a tour guide is your best bet to see as much as possible efficiently. A tour of St. Petersburg on one of the many canal boats combined with a bus tour is a good way to get an overview of the city. Most people want to visit one of the most famous museums in the world, the Hermitage. Day trips to Catherine's Palace and to Peterhof are are very interesting.