Russian Visa and Passport Information
Visas and passports are required by all visitors to Russia. There are two popular types of Russian visas - "tourist visas" and "business visas". In most cases a "tourist" visa should be satisfactory - unless you are planning to go to Russia for longer than 30 days. In this case you should apply for a "business" visa.
Three month tourist visas do not exist anymore. If you need to stay in Russia for longer than 30 days then the only option is to get a business visa. Business visas can be valid for up to 12 months. A Russian Business Visa is supposed to be issued to people who are going to Russia for business purposes, but because this type of visa allows a person to stay for longer, and enter the country more than once, it is also used by ordinary travelers who need more flexibility.
Note, that you must register your visa within 3 working days (except Saturdays and Sundays and public holidays) after entering Russia, or you will have problems upon leaving the country.