Campus visits are the most effective way to evaluate a college campus.  That's why independent educational consultants visit college campuses regularly.  You can look at video tours online and lovely pictures, but nothing beats the experience of being there (especially when classes are in session).  You aren't just seeing it,  you hear it, you smell it, you get a feel for the physical layout of a campus, you get to see how people move about on campus, how they interact with each other in social spaces and best of all, you meet students.  

A campus visit should include the official tour and admissions talk and the student should be signed up for this before arriving on campus.  A college likes to know that a student and their family was interested enough to personally explore their campus and its offerings.   Many colleges offer overnight stays and/or attendance at a class.  Admissions offices will usually honor requests to meet with a professor or see a particular lab.  

Arrangements for college tours and visits are usually made through the colleges admissions office.

To see multiple colleges and universities on one trip, Go See Campus is a web resource thats helps plan your trip.