All necessary information to obtain a visa to Italy for Russians is on the official website of the visa center in Italy. We can add list of documents with some comments:

General information

Applying for a tourist visa by the applicant personally (if not, add a lot of cases with power of attorney).
A tourist visa allows to stay in Schengen countries up to 90 days in each half of the year (but more often a consulate puts exactly travel dates, so check to be sure that retuning date in the form, tickets and hotel reservation 100% match!). After receiving the visa it is better check the number of days for which you have been given a visa.
Maximum time to apply for a visa is three months before travel. Since the submission of documents to the receipt of passports it was 7 days.