How to get a confirmation for travel visa:
When applying for visa, you should say that you are travelling to Russia as a tourist. Not for work! Getting permission to work is very difficult in Russia...sorry) To confirm your intentions you will need flight tickets and an invitation (from my previous experience this is enough). To get the invitation you need to book a hotel (I recommend "alekseevsky" hotel), then go to ivisaonline.com, and fill out the form and make the payment (~20€), after that you will receive your invitation. Then you can cancel your hotel booking (Alekseevsky hotel does not charge you for that, they accept payment upon arrival).