You can't work in New York without a U.S. work permit. In fact, you can’t even stay in the U.S. for more than 90 days without a visa.

At least that much is simple enough to grasp. The difficulty comes with the sheer number of visas available, the particular conditions attached to them all, and the intricacies of immigration law. Getting the correct visa paperwork should be a priority for you  —  before you begin think about houses or schools or shipping companies, you need to get your head around the immigration and visa system, and U.S. visa and work permits.

First, it’s important to note that the U.S. Citizenship and Immigration Services website is an invaluable source for up-to-date information and forms for all types of U.S. visas. This is the branch of government you’ll be dealing with when applying for visas, so take some time to familiarize yourself with the site and various buzz words that will show up again and again. You can access and download all appropriate forms, including work permit applications.

Second, for those with the money to afford it, immigration lawyers can be a fantastic way to navigate the often confusing and frustrating layers of rules and red tape that make up U.S. immigration law. It's important that  every form in the immigration process is perfect, and the authorities will follow up on even unintentional mistakes. Therefore, if you have the ability, hiring a lawyer can save angst down the line. 

Last, but not least, don’t forget to budget for the visa itself. It’s easy to forget in the midst of a major move that, like shipping and rental costs, visas cost real money  — often a couple of thousand by the end. Even several years after approval, certain visas will require additional payments to be made in order to finalize changes or to process extra forms. Be prepared, and have your finances in the best shape that you can.

U.S. Visa Types

 The U.S. has roughly six different types of visas: 

• Immigrant (permanent, employer-sponsored workers)
• Family (fiancés, family of current U.S. citizens and green card-holders, family of refugees)
• Humanitarian (refugees and asylum seekers, victims of trafficking, battered spouses and children, etc.)
• Adoption (children adopted overseas and brought into the U.S.)
• Military (citizenship for military members and their dependents)
• Temporary workers (specialized, time-limited professions, athletes, actors, etc.)
• It's worth noting that there is no such thing as a "New York visa". The system is centralized, and so U.S. visa types are set by the federal government.

The above list is by no means exhaustive  —  in fact, trying to categorize visas too simply is a mistake. There are specialty cases and exemptions for incredibly specific circumstances, and myriad rules applying to them all. So, for the sake of brevity, let’s assume that you’re simply applying for a regular immigrant petition leading to a green card (that is, permanent residence).

Entrepreneur visas

Recent U.S. government actions to boost the economy have made it easier than ever for individuals and small businesses to build startups in the States. A few different options are now available, depending on company type.

A New York International article by Lina Salazar provides a brief overview of the system and the new laws. The Startup America Partership website also features startup news and some success stories.

Immigrant petitions

Non-immigrant petitions are temporary; immigrant petitions are permanent. The key word here is "petition"  —  you are asking the U.S. government to consider whether you can be allowed into the country with the right to reside and work. It is allowed to say "no."

Since a green card (the eventual outcome of a successful immigrant petition) gives you the right to live in the U.S. with no time limit and to work in any field you choose, they are more difficult to get than you might think. We'll address them in a later section.

If you already have a job arranged, then your employer will need to file the petition (starting with form I-140) for you. This form informs the USCIS that a company wishes to employ you and it requires you to become a resident in order to do so.

If you don’t have specific work lined up, getting a visa can be harder. If you have special skills that are desirable, you can apply to be a permanent worker. However, applying to become a resident with no family or work already in the U.S. is difficult. This is because as part of the petition process you must guarantee a certain level of financial security, enough to keep you off of welfare for several years. Certain visas (such as the fiancé / spouse visa) allow a family member to sponsor you with an Affidavit of Support, promising to financially support you in the event you're unable to support yourself.  

A basic immigrant petition will need the be filed at least a year before you move. Once the initial application is submitted, it must go through various checks, and you will be contacted to provide information ranging from your criminal history to your medical health. You will also need to pay a number of fees (though they may be covered by your employer).

Once a petition is approved and enough supporting documents have been supplied, it’s simply a matter of waiting for the application to work its way through the busy system. Remember to keep at least two copies of everything you file.

Fiancées / spouses

If you’re moving to the U.S. to get married (congratulations!), then there are some very specific rules you need to follow.

It's important to remember to apply early. It can take over a year from the time you submit the petition to the time the application is approved, and the last thing you want is to have your big day ruined by one of you not being allowed to be there.

The U.S. citizen will need to file the petition for the foreign parter to enter the country, and the supporting forms and documents you will also need to supply can be a tad overwhelming. The government places a huge emphasis on ensuring marriages between a U.S. citizen and a foreign national are valid because marriage visas can sometimes be a "back door" method for getting a green card. Expect to send love letters, photos of the two of you, flight tickets from family trips, engagement ring receipts, and anything else than can help your cause.

You don’t need to have a job lined up if you are applying for a fiancé visa (called a K-1 visa) but your fiancé or their family will need to financially sponsor you. Once you enter the U.S., you have 90 days to get married or else the foreign partner risks becoming an illegal immigrant.

The foreign partner can also immediately apply for permission to work with form I-765, which allows him or her to work in the U.S. until the green card arrives.

If you are already married, form I-130 petitions the government to allow your spouse to become an immigrant.  

Forms

Beside the large database of forms available on the USCIS website, your application will require you to include various pieces of paperwork with your petition. Being prepared is key, as is being consistent. A brief list of the things you might need includes:

• Birth certificate (both yours and any children’s)
• Death / divorce certificate (of any previous spouses)
• Police check (from all countries in which you've resided for a year or more)
• Complete work history with contact details
• Financial records
• Proof of relationship
• U.S. employer details / proof of employment
• Proof of specialized skills
• Medical check from an approved, certified doctor
• Affidavit of Support from a U.S. citizen
• All USCIS forms are free to download. Never pay someone for an immigration form. It’s a scam, and may as well be an outdated version. 

Help and resources

The immigration system is complicated, but it also can be managed with simple organization and attention to detail. A valuable online community can be found at VisaJourney to help you along the way.

In addition, Wikipedia has helpful explanations of the various U.S. visa types and a helpful overview of the system as a whole.