Almost every single university in US has an international student advisor that you can talk to about the university and any question or concerns that you may have. They can also help you with the application process and can connect you with other students who attend university and he can tell you it's experience.
University requirements will differ depending on which university you attend. You can get much of infos that you will need on the university’s website.. Maybe this might help you more than our replies : http://www.studying-in-us.org/application-process/