For many high school students, especially those in the 11th grade, Spring Break is the designated time for college campus visits. I wouldn't go so far as to say this is "normal." Lots of students do this, yes. But lots of students don't do many--or any--visits until they're seniors and visit only schools they've been admitted to. And plenty of students don't visit a college at all until they show up in the fall of their first year as college students. What's "normal" is up to you and what you think is really best for you. While I don't recommend skipping college visits altogether, neither do I recommend going on big multi-campus trips just for the heck of it.
However, if you're a younger high school student--in the 9th or even 10th grade--I urge you to consider going on some "practice visits." Unless you live in a rural area, there should be at least a few colleges and universities near you that you can tour. Sign up for three or four tours, and do your best to get the full range of college types. Here in Houston I recommend touring Rice, the University of Houston main campus, and Houston Baptist University. If you live in the St. Louis area, for example, consider Blackburn College in Carlinville, Washington University, and U.M. St. Louis. This way you can get a sense of what a big state school looks like and how it differs from a medium-sized private school and how they both differ from a small private school. At this point, in your practice runs, I wouldn't even worry much about the differences in cost or curricula. You're just trying to get first-hand knowledge of how different types and sizes of schools feel.
Why bother visiting colleges you're not interested in attending? Isn't that a wast of time? Not necessarily. For one, you make sure you get a variety of experiences early. Imagine you do a big East Coast trip to visit Georgetown and G.W. in Washington D.C., Columbia and N.Y.U. in New York, and then Harvard and Boston University. You've hit six big-name schools with great reputations...but they're all medium to large private universities. If you're sure that what you want is a large private university in an urban area, that's fine. But if you're not sure how different sized schools feel and operate, then it may be a time and money saver to get a feel for that near home.
It's also good to get a sense of how universities work from schools that you have no emotional attachment to. In this sense, think of college visits like any other shopping trip. It helps to survey what's available and do some research before walking in to a store eager to buy something. You'll be a lot less susceptible to emotional sales tactics and a lot more confident in your control of the situation. Maybe you won't be so eager to attend a school because you were really impressed by the dining hall or the friendliness of the students if you already have a sense of what's available elsewhere.
It's also smart to get a few visits out of the way at places you're not necessarily interested in attending just to have some practice and be less jittery. You don't want to waste a visit to a top-choice school because you're nervous that you may say the wrong thing or that things won't look the way you expect them to look. If your first visit to a contender is your fourth or fifth school tour, you'll already be an experienced pro and can really focus on what you need to for that visit.
And, of course, there's the thing that the admissions departments of the local schools you use for practice is hoping: that you'll end up really wanting to go that school, even if you hadn't planned on it. As in any relationship, you just may find your match in a place you weren't expecting.