Plan to live on campus. If not, spend as much time as you can on campus. This school is NOT for commuters. If you allow yourself to join in on the campus activities you will have the time of your life.
I would tell myself to explore more colleges and actually visit them. Don't be afraid to venture outside of your comfort zone because you may find that where you truly belong is way out there.
Apply to more scholarships if you plan to live on campus rather than pushing it off due to the massive projects of senior year. College life is beyond expensive to handle.
Go to the campus and ask students about what they think about the school. Students will give you the most relevant description of everything from dorms to classes.
I made the mistake of only applying to one school. I made the right choice, but remember to keep your options open and apply to as many places as you can.
Visit the college you plan to attend before paying anything. You have to physically see the campus and its students before oyu can make a good decision.
Select a school where your child has the most oppertunity to meet people in their carrer field. These are the people that get you jobs.
Make sure that you look closely at the larger campuses and see it they are truely lagit. Smaller might be better!
I would tell myself to focus on critical thinking skills and prepare myself to be ready for lots of writing.
Visit the campuses, the area around them, and the scholastic areas. Not necessarily in that order!