I think that visiting the actual college is a much bigger deal than going to an information session in your area. And by "visiting," I mean spending most of the day there: take a tour, then meet with someone in admissions or a counselor, meet a professor, go to a class. Take notes, ask questions.
Parents, take note: let the kid do 90% or more of the talking.
It's easy to attend an organized event that's local, and while doing that is showing interest, it's a few levels down from spending the better part of a day at the college.
I agree that's it's worth attending the local events, but given that a lot of people are doing the same thing that day, they don't give much in the way that makes a prospective applicant stand out.
Another advantage of spending some time at a college is that if the student attends, s/he knows a bit about what to expect.
