If you have received multiple acceptance letters, Congratulations!! Your hard work has paid off so now must decide which one to accept. Assuming you only applied to schools you were seriously interested in attending, you will need to decide what factors are most important to you.
At the top of your list should be the cost and the amount of the financial aid package is critical. Depending upon your situation you may decide to attend the school that has the most generous financial aid package in terms of free money (grants and scholarships). These awards do not have to be paid back so the more free money you get the better. Especially if one of the schools you are considering is more expensive than the others.
You should also consider the location. Are any of the schools out of state? If so, the tuition for an out of state student will normally be higher than in-state. Also, how important is it for you to be close to home? Do you think you'll get homesick or do you look forward to getting away from your parents and experiencing a new part of the country?
Do you think you would excel at a small school or a large institution? Do you plan to get involved with any clubs and organizations? If so, do any of the ones on the lists provided by the schools look interesting? What about the student to teacher ratio and the demographics in terms of diversity? These are all the things you need to consider when making your decision. Hopefully I provided some food for thought.