Visiting colleges is an important step in determining where your child will apply. It shows colleges that you are interested in coming to their school. With college visits, you'll want to have prepared some questions in advance that will give you information you can't find online or in their view-books. Ask open-ended questions to, hopefully, engage in meaningful conversation.
What are colleges are really looking for? Students who really want to attend a particular college need to be able to convince the school that they will stay for all four years at that one school. Universities want students who will turn down other amazing offers of admission, and will attend their own college instead. No matter what. How do you demonstrate that interest?