Types of permanent admission to the US.
If you want to live in United States permanently you need to get a green card, this is what qualifies you as a permanent resident. The Law Blog says there are several different ways that you can qualify for a green card but none of them are easy. Your best chances will be if you already have family in the United States.
The first way that you can get a green card is to enter the county on a family visa and then apply for one. This is by far the most common way that people are able to qualify these days. In this case you will need to have a close family member who lives in the US that will sponsor you. Exactly who qualifies as a close family member varies so you will have to check the current rules. This person will have to file a petition on your behalf. If that is approved you may apply for a family visa and if that is approved once you get to the US you can apply for a green card.
The next way that you can get a green card is to apply for a work visa. These are a lot harder to get than they used to be and as a result only a small number of people are able to enter in this way. In order to qualify you have to have a job offer from a company in the US. Your employer has to fill out the petition on your behalf, during which he needs to be able to show that he couldn't find an American who could do the job. This is why it is so hard to qualify. If you are successful you will get a work visa allowing entry to the country at which point you can apply for your green card.
Another way that you can enter the US permanently is by applying for refugee status. This requires that you be able to show that you can't go back to your own country because you will be persecuted. Qualifying in this way is very complicated and you are going to need legal help to make your case. If you are granted refugee status you will be able to get a green card.
The last way that you can enter the United States permanently is by winning the diversity lottery. Every year a certain number of green cards are made available to allow people who wouldn't qualify by other means a way to enter the US. These green cards are then divided up by country with each country getting a certain number. At that point anybody who meets the basic qualifications can apply for one of these cards. There will then be a lottery to determine who gets them. If you are one of the winners you will be given a green card and allowed to move to the United States.