USA green card: Consult an expert before applying
Let's take a look at a real time example of the procedure you would have to undergo, with the most probable time-lines collected form a leading immigration help agency. Following is a list of the applications that were submitted:
Immigrant Petition Adjustment of Status Work Authorization Advance Parole
The couple mentioned below were living in New York, and the adjudicating authority was the New York City.
June 26, 2009: All applications sent via Federal Express for overnight delivery to USCIS July 1, 2009: Receipts issued by USCIS for all applications July 4, 2009: Notice issued by USCIS providing the place, date, and time for the biometrics appointment July 22, 2009: Biometrics appointment July 24, 2009: Work Authorization approved August 6, 2009: Advance Parole approval approved September 5, 2009: Notice for Interview Request issued providing the place, date, and time for interview October 9, 2009: Interview for adjustment of status (stamp placed in passport) October 9, 2009: Permanent residency approved
The green card was received in 3 weeks.
The major advantage in this case was that an expert immigration attorney had handled this USA green card application case. I am pretty certain that without such help, it would not have been possible to achieve this result within such a short span of time, since there were many documents and legal proceedings involved.
So in the end, I would just like to say that if you or your would-be spouse are going to apply for a USA green card, it's best to take professional help, since you would be certainly taking the much longer route if you are on your own.