Valid for up to one month, a tourist visa can be obtained with the following documents:
- Two completed and signed visa application forms;
- One recent passport sized photo, signed on the back;
- A tourist confirmation either from the hotel where you will be staying or from your travel agents (Russian or otherwise);
- A tourist voucher, also issued by the hotel or booking agent;
- A valid passport.
The tourist confirmation is basically a document stating that you have booked accommodation for the entire duration of your stay in Russia. Most hotels will offer this service automatically (they have to be accredited to the Ministry of Foreign Affairs). If you are planning to travel around, or are staying in alternative accommodation, then there are a number of agencies that will issue you with the necessary tourist confirmation and voucher, normally for a set fee plus the cost of one night's accommodation. Note that whoever issues the documents will need to register you when you arrive in Moscow.
The photo you supply should be genuinely recent, as Russian officials - bless them - can be peculiarly unnerved by such things as changes in hairstyle and the absence or addition of spectacles.
Registration of tourist visas will normally be done by the hotel where you're staying, without your involvement, and should not take more than 24 hours.