I'm infamous with my students for telling them that every campus tour is (basically) the same. Guides will take you to the campus's flagship building (usually a particularly impressive science or business facility or whatever is the most recently constructed or renovated), the dining hall, the library, the athletic facilities, and a residence hall. They'll consciously take you around the token ugly building (every campus has one!) and, in the end, you'll have received a perfectly pre-packaged glimpse at a school - usually accompanied by nothing that can truly help you understand what it might be like to be a member of their student body.
I encourage my students to employ the following strategy: Go BEYOND the tour and the information session. How? Here are my tips:
Sit near (or at) the front during the admission session. Take notes for later to help you remember key items after you've returned home - or to help you ask questions at the conclusion of the session. If the session presenters are students, don't hesitate to ask them why they chose the school and if they would make the same choice over again if they were in your position. (They'll say yes - but it's the reasons WHY that will be important to you.)
Stay near the guide when you're on tour. You don't want to miss anything that he or she says and you certainly want to be close enough to ask questions as they arise while you're walking around. In big groups, this can be a bit of a challenge, but the end result is worth it.
If the tour doesn't visit the academic building where you most likely will spend much of your time as a student (e.g. the humanities building if you're thinking of majoring in English), make sure your guide identifies it for you so that you can return to visit on your own after the tour.
TRY THE FOOD! This one is in all caps because many tour guides will brag about the quality of food on campus - while in the next breath they'll tell you that they use the majority of their available food swipes at other on-campus eateries. So while you're on campus, be sure to find out if the dining hall food is to your taste - or not!
Wander on your own - with or without your parents. After the tour concludes, be sure to get out and explore campus a bit on your own. Talk with students who aren't employed by the admission office and ask them about their experiences. Visit the student center and see what goes on in between classes - then see if you can truly picture yourself there for four years.
Finally, if you still have lingering questions following a tour or info session, inquire about meeting with a financial aid or admission officer while you're on campus. Appointments are usually available and you don't want to leave campus missing any key pieces of information!