Nothing wrong with Aeroflot, maybe a little more headache
price wise less expensive, service is decent.
Best to have a native guide, could be your friend or someone you meet over there, ideally someone you can trust. In large city's downtowns quiet a plentiful people speak or understand English. Many of young crowd have mixed Russian-English, good amount of English basic words are used on a daily basis. "Okay" is used as often as "Da".
In terms of a stay-in place your options basically are hotels or residential rental (apt, house, ranch, etc.) renting out done either on daily or monthly terms. The residence owners usually like to have some kind of prepay preferably in dollars. Residential rental can be sometimes risky, many times less expensive than hotels, in most cases room service in these rentals can be arranged to whatever degree you may wish.
Russian currency, rubles are used every where else where formality is necessary ;). Currency exchanges can be found at most banks and practically on every corner of busy streets. I don't recommend to get involved in money exchage in private sector and people you don't know just to be on a safe side. Plenty of ATMs in downtown areas your visa's most likely will work at a hight transaction rate. In large cities in many places credit cards and debit are accepted. Some of these places can charge extra % for processing CC.
Many areas to explore along with your usual tourist attractions - luxury/vip, nightlife, underground scene, hitch highcking, suburbs/country lifestyle, and fishing/hunting.
Shopping bags stores sell as an option at extra charge LOL, but it's true.
And beer you can drink almost anywhere in any shape or form, anytime!
In general like in any other places far of your home you should be always careful, don't loose your guard at any times, which prevents from welcoming unwanted situations. Russia has its unique bueaty at all seasons, for the first time ideally go at the end of spring and during whole summer time. Plan ahead, don?t drink too much and be ready for lots of fun and new experiences.