1. The first category is a tourist visa. However, the immigration officers frown upon granting a young, pretty woman from Russia such a visa. The reasoning is that she will find someone to marry almost as soon as she steps off the plane and never return home, possibly receiving government assistance and becoming a burden to USA national economy. Not to mention the fact that trying to obtain a tourist visa for a woman you are intending to marry is kind of stretching the truth a bit...perhaps illegal.
   
2. The next possibility is that of obtaining a student visa. This would really only be a workable solution in a very specific situation. If your intended is a student, has good English speaking ability, and can meet other eligibility requirements, this MIGHT work. She will probably have to take tests to substantiate her claims. And YOU may be required to provide evidence of support for her during her intended stay in your country. At the very least she will need to show that she has the money to pay for school (or scholarship) and some form of support. It may be a lot longer and round about process than you had bargained for. I would rather discourage you from doing this - unless she has already initiated the process and is well along when you meet and decide to perhaps marry.
   
3. You could perhaps try to obtain a worker visa. This will really depend upon her occupation. And whether or not this is an area deemed "high need" by your government. One of the current areas of need is nursing - in the USA. So, if your Russian girl friend is in the nursing field, this MAY be a possibility. I believe that she would need to basically have a job lined up already and that company or organization acts as her sponsor. It goes without saying that for something like this she will need excellent English ability, or whatever language is prevalent in your country. She will also be expected to go to work right away. This may work for some Russain ladies, but probably very few. You can find out more information regarding worker visas (and any of the other types mentioned in this article) by visiting the immigration web site in your country.
   

Referring to the USA, you will then have a period of 90 days in which to decide if marriage is right for the two of you. At the end of those 90 days, she must either be married or return to her former Soviet Union home. You also are acting as her sponsor during her stay.

If things do not work out as expected and the decision is made for her to return home to Russia (Ukraine, or the FSU), you are responsible for providing her with plane tickets home. You also notify the USCIS (the main USA government agency responsible for immigration issues) of the situation. If you have been honest in all respects, you should not have any difficulty if you decide to try again with another woman in the future.

This discussion is very general since requirements, forms and fees are constantly changing in all countries.  All of these documents must be translated into English (or your Country's official language) by a certified translator.