I'd say you'd want to consider four factors:
1. Reputation of the school
2. How much it's going to cost
3. What you want to major in
4. The overall "feel" of the place
There are often tradeoffs between these elements, so you will have to weigh them against one another. For example, there are many excellent private schools out there that will cost you $$$$$ to attend. Perhaps you could get just as good an education through an excellent state school system, such as that of California, Virginia, or Texas, which have a lot of different campuses and where tuition can be comparatively lower, even for out-of-state students.
What you major in can often be as important a factor as where you choose to go. Which is more valuable -- a B.A. in English from Harvard, or a B.S. in Computer Science from the University of Maryland? In terms of immediate marketability it may well be the Computer Science degree, but you need to make sure that wherever you get your degree, the education you get in your area of specialty is top-quality. If you think you know what your major will be, check out that department in your candidate school -- how big it is, what its general reputation is, what the faculty is like, etc.
Lastly, you will want to make at least one visit to campus to try to get a feel of the place and see if you like it. You're going to be there for at least four years. It needs to be a good fit. Do you prefer a big campus with a lot of students or something more intimate? Do you want to be near a big city or are you okay being near a small town? Do you want to join a fraternity or sorority? (Some schools have very few.) Do you want a school that's mostly concrete, or something that has more wooded areas? What size classes do you want? All these elements may contribute to the feel component, and while feel may not be the most important factor, it can often be a tiebreaker between two otherwise excellent candidates.
Good luck whatever you do.