It was important to my son and me to attend some classes, so we chose to visit schools in the spring of his junior year rather than in the summer.
College websites gave all the info we needed to plan trips – how to get there, where to stay, how to register, where to park, where to eat. The only issue was figuring out class schedules and locations. We were able to do that once we were there.
It takes a surprising amount of time to visit – info session, tour, a class or two, and lunch in the cafeteria (highly recommended) takes all day. We found just walking around campus to be invaluable: Are the kids friendly? How does it feel to your child? Although many parents say their kids reacted to minor things – for instance, a gray day – I'm a big believer in intuition, so if your child develops a like or dislike for a college, better to know through a visit before applying.
We loved visiting the schools together, and we were glad we visited because we ended up not clicking with one of the schools that had been very high on our list.
The other reason to visit is that every college asks why you want to go to that specific college. It's very hard for 17-year-olds to convincingly convey that they REALLY want to go to that college if they have never visited but have only seen the website.