When deciding where you want to apply, you should keep in mind the factors that are most important to you. Some important factors to keep in mind are:
Cost. Is the college within my budget? If not, what do they offer for work-study and financial aid? What about scholarships?
Academic Record: Is the college Ivy League? Is it highly competitive? Will it stand the test of time?
Location: Is this college in an area where I would choose to live for four years? Do I prefer a rural or urban campus?
Size: Do I want to go to school with eight-hundred students or thirty-thousand students? How large are the classes? What is the faculty to student ratio?
Student Body: Are the students who go to this school diverse? Is it a liberal or conservative institution? Is it a religious institution? Is it sports-centered or arts-centered? Do most of the students live on campus of off-campus? Are there people there that I think share some of my same interests?
You should decide what aspects of the school are most important to you, and then decide which schools to apply to based on those factors. Most every college has a website that tells all of the information you will need. If you can't find all of the information you need, you can contact the college admissions office. If you have no idea where to apply, you may want to purchase a book that lists the various colleges in the country. In that case, you can look at the different states and find colleges there that fit your requirements.
Act, Inc. lists the following criteria on their College Search Checklist:
High school courses required
College credit for exam scores or high school courses
Cost of attending college
Merit and need-based scholarships
Career placement/advising services
Study abroad programs
When you decide which colleges you want to apply to, go visit them! If it is all possible, a campus visit is the best way to learn if you like the vibe of the school.