I've been a campus tour guide for our admissions office for the past 3 years. The biggest advice I can give is ask questions. Too many times, I'll be giving a tour, and all the students are silent for the whole time. The parents ask questions, but the students don't.
Most times, the type of questions your parents ask won't be the questions you'd be asking. The tour guides will be throwing information at you, and there's a lot of information, but we can't possibly cover anything. If you're worried about what your parents will think about your question, come up after the tour while your parents are using the restroom or something. Or ask for the tour guide's email address.
Plus, getting questions makes our job more interesting. On a busy month, I can end up with about 15-20 tours/month (average is more like 8-10). If nobody asks questions, then I'm repeating essentially the same speech 15-20 times. That can get real boring real fast, and it has an effect on the overall quality of the tour. If the guide is bored, are you really going to want to go to that school?
(if you're planning on applying to Syracuse University, send me a PM (for what it's worth, if this affects your decision, Syracuse is about a 5 1/2 hour drive from Manchester, and it's a fairly easy drive))