Application forms are available free of charge at any U.S. Embassy or Consulate. Apply for the correct visa. Make sure the visa application is correct and complete. Some travel agencies are known to submit visa applications stating that the purpose of the trip is other than the real purpose. Be prepared for the interview.
Consuls have approximately three minutes to spend with each visa applicant.
Be forthcoming about the information you feel is relevant to the purpose of your trip as well as your ties to Russia.