Your employer must demonstrate to the Department of Labor that it is unable to locate qualified or available U.S. workers for your position in the geographic area where you work. This process is currently taking at least 12 months.
Form I-140, Immigrant Visa Petition
Your employer must then file a petition with the USCIS and demonstrate that you qualify for the position as described in the labor certification. This may take two to twelve months.
Adjustment of Status (Form I-485)
This is the application filed by you and your family members to "adjust" your status from temporary worker to permanent resident. This step currently takes six to eighteen months, depending on visa availability.
Some permanent residence categories do not require labor certification (intracompany managers and executives, and "outstanding" researchers, persons of "extraordinary" ability and persons of "exceptional" ability whose work is in the "national interest").