There is an application fee. It varies, but this fee is used to pay for various administrative costs. (Or so they tell us…) Ivy League schools (Harvard, Yale, etc.) tend to cost more than their public counterparts. If paying the application fee would create a financial burden for your family, regardless of the fee amount, check with your prospective university to see if a fee waiver is available.
If you have not already, you need to take the SAT or ACT exam. Check with your university to see which test is preferred; some accept both. For some elite universities simply taking the ACT or SAT is not enough. Harvard, again, is a good example of an upper-echelon university which requires further testing. Its stringent application process obligates applicants to also take three SAT II exams of their choice. (These are subject-specific achievement tests.)
If you want to attend a school with competitive admission, have a backup plan. You must have alternates. You absolutely must. Even if you apply early decision at Yale with a 1520 SAT score, you need to apply at one or more alternate schools to make sure you have somewhere to go if the worst happens.
One or more letters of recommendation may be required. Ask teachers who saw you at your best to help you with these. Whenever possible, ask teachers who teach a subject similar to your intended major. Are your teacher recommendations due by the end of January? Tell them TODAY! Teachers are people, too, and they are often quite busy. The more time you give them to craft the letter the better it will portray you.
If an essay is required, it is generally a crucial part of the application process and requires an article to itself.
The selection process varies. Factors such as GPA, test scores, etc. are universal, but there are others which you need to know about in order to have the best chance to be accepted where you want. Did one of your parents graduate from your intended university? If your college considers this there should be a place in the application to list this. Are you a minority? Colleges love to have a diverse ethnic population. Many may frown upon this, but if you fall under this category you may as well run with it! Do you have an obscure talent? Put it on the application! You never know what your college is looking for!
Know your deadlines. If you have to declare an early-decision before October 1st, you better try to take care of it in September. Don’t be one of the students who feels that his/her time is more important than everybody else’s.