If you are a foreigner and got married to a United States citizen, you will be eligible for a green card. But to get a permanent visa, it will take 12-15 months and subject to the annual quota in providing green card to the immigrants. During the processing time, you can stay in the US if you have a student visa or a working visa.
The US also offers K-1 visa to the fianc‚/e of a citizen. The application for visa is filed on a USCIS form I-129F by the sponsor or the citizen on behalf of the fianc‚/e, who will then be interviewed at a US embassy or consulate in his/her native country. If the visa is granted, the fianc‚/e has to marry the US citizen sponsor within 90 days of his/her entry to the country. The fianc‚/e can also apply for visas for children to enter at the same time.
If the marriage takes place abroad, the green card petition will be filed through a US embassy or consulate. The procedures usually take between six to nine months to complete and subject to green card quota. Those who apply abroad will also wait out side of the US during the entire processing period.
One may not enter the country as a non-immigrant with the intent to marry and live in the US permanently. The US will not admit people who intend to marry and plan to live in the US permanently as a non-immigrant. If the authorities knew the intention, they would deny entry and possibly bar entry for five years under summary removal procedures.
For immigrants who want to stay permanently in US, the government conducts a lottery in which it randomly selects 50,000 applicants from across the world to provide green cards. The administration will hold such lottery in 2007, for which it has short listed 82,000 people out of more than 5.5 million applicants.
Manu Goel site http://www.myusgreencard.com, a portal which helps in filling out the application forms for US green cards and helps in ensuring that the forms are complete in all respects, to get more information if you are planning to visit the US or if you are thinking of applying for a US visa.