In my experience, it's best and least costly to go to a one-stop specialized agency for a Russian visa. I found this one to be pretty good: www.gotorussia.com. There are substantial quality differences between individual Russian consulates in the US. Those who decide to get their own invites/visa apps, must go to their assigned consulate (usually the closest geographically). Agencies can go to any consulate, and naturally choose the most competent & user friendly (i.e. the one in San Francisco). So just go to one of the agencies, and they'll take care of the required paperwork usually at no extra charge (other than postage/FedEx fees).