You have to have a good idea what you would like to major in. You don't have to decide, but you should have at least a clue. The classes in high school that you enjoyed the most or had the best grades in is a good start. You will need to ask which colleges/universities offer those types of classes.
You also have to look at what the class sizes are. Some people prefer the lecture style classes of a big university while others prefer the intimate classes of a small college. You need to figure out what suits your learning style. Once you know, then you can ignore the ones that do not work for you which narrows the pool you are choosing from.
Lastly, what can you afford? Colleges try really hard not to lose out on a prospective student due to high tuition and offer financial aid as best they can, but you are expected contribute.