Your next step is determining how and where to apply for your visa; for more information, see Nolo's article get the book U.S. Immigration Made Easy, by Ilona Bray (Nolo).

Limits on Activities in the U.S.

Your visa allows you to enter the United States and to engage in certain activities while you're there. For example, if you receive a student visa, you're allowed to study in the United States -- but not to work off campus (unless you seek special permission) and not to stay permanently.

How Long Your Visa Will Last

Just as nonimmigrant visas vary in purpose, they also vary as to how long they last. Each nonimmigrant visa is given an expiration date according to what the law allows. Most can also be extended a certain number of times.

An important caution: The expiration date on your visa does not indicate how long you can stay in the U.S. once you arrive. It indicates only the period of time during which you have the right to enter the United States using that visa. How long you can stay is shown by the date on your "I-94 card," which is a small white or green card you'll be given when you enter the country.

If your visa is "multiple entry," however, you can use it to enter the United States again, as soon as you like. If it's not multiple entry, you can use it only once.