Careful planning is both necessary and wise. You will be required to prove to the university, to the consular officer (the person at the U.S. Consulate who issues visa stamps), and perhaps to the U.S. Immigration and Naturalization Service that you have sufficient funds to cover your living expenses (housing, food, clothing, etc) and health insurance, as well as university's tuition and fees.
So how much money will you need? You can get a general idea about expenses by looking at catalogs or application information provided by the university. Remember, however, that tuition rates vary tremendously. State (public) universities are generally, but not always, less expensive than private institutions. Some private institutions may be able to offer scholarships that state schools can not. Two-year or community colleges are usually less expensive than colleges and universities offering bachelor's and graduate degrees.
The cost of living in different parts of the United States also varies. In general, living in urban areas (in or near a big city) is more expensive than living in smaller towns or rural areas. Renting an apartment in a big city can cost twice as much as it does in a smaller town because there is such high demand for housing in large U.S. cities. Likewise, food, clothing, entertainment, and other living expenses may be more expensive in a city.
There are hundreds of resources available online that offer scholarships or access to search for scholarships, but not all are legitimate and some are there just to scam students. Learn how to spot a scholarship scam and locate the resources that are tried and trusted.
Creating a Budget
Budgeting is a continuous process. At this stage, work on a "big picture" budget that will include tuition, room and board, transportation, and living expenses. Later you can be more specific, taking into consideration all the additional expenses of moving and settling in. One very important factor in the "big picture" budget is health insurance, which can be as little as $1,000 annually for an individual or as much as $5,000 for a family.
Students who study abroad often regard it as the experience of a lifetime. It's an exciting time when you can learn almost as much outside the classroom as within it. But it can also be very expensive, and it takes some advance planning. By creating a sensible budget and sticking with it, you can better manage the financial side of studying abroad.