Assuming that your fiancee is a US citizen, the first thing that you need to do is to get married to your fiancee and then she will need to submit an I-130 petition on your behalf. It will take about 9-12 months for the petition to be processed before you will get your immigrant visa interview at the US consulate in your home country. After the interview, you will be asked to file an I-601 waiver and you will need to submit substantial evidence to show that your wife would suffer extreme hardship if you are not allowed to return earlier.
Answered on Oct 15th, 2012 at 2:27 PM