What do I need to have to travel from Russia to USA by airplane?

I have a friend that lives in Russia and wants to fly to USA , what documents will be needed? Where is the best place to get plane tickets or compare prices?

I've had the best luck with travel agents. He'll probably need a tourist visa as well as his airplane ticket. Have him contact the US Embassy for exact details.

Comparing Prices: Internet
Documents Needed: Passport
Other Required Items: Money, Money, Money!!!

Your friend will need a visa. More about it is here:
http://moscow.usembassy.gov/consular/consular.php?record_id=nivservices
In short - you'll have to invite your friend, and he/she need to prove intention to return back to Russia and availability of funds for this trip.

The tickets can be bought on Internet. If you're buying tickets, you can use http://www.kayak.com (very good place for comparison shopping) and your friend can use http://www.pososhok.ru (in Russian)