As you narrow down your list of which schools you would like to attend, it is advisable to visit the campuses of the business schools on the top of your list. This can not only help you identify which schools would be the best fit, but it can also have a positive impact on your application. Many schools keep track of who came for a campus visit and your presence will demonstrate serious interest in the school.
The best times to visit are when school is in session. That's when you will get the most accurate picture of campus life and the school might be better prepared to accommodate campus visits during the academic year than during school breaks or the summer session.
Some admission committees make themselves available to meet with prospective students to answer questions. If that is is the case with the school you are visiting, be sure to take advantage of the admission committee's accessibility. If that is not the case don't force it, because negative interactions with professors and admissions staff can also find their way into your file. Use the visit as an opportunity to get all your questions answered, but do your research first and try not to ask all the questions that can be easily answered online. One example of information that is worth looking into is job placement statistics for the most recent graduates. Avoid knocking on the door of the school's placement office for that information as they are devoting full-time efforts toward current students.
Often as part of the campus visit prospective students are paired with a current student or invited to sit in on a class. If you have a special interest or a specific situation, you might ask to be paired with someone who shares your interest or could address it. Try to ask questions of your student guide that would draw out their opinions, rather than yes-no questions. How would they describe campus life? How would they characterize the competitiveness of the school? How accessible are the professors?
If sitting in on a class is part of the visit that is great to observe first hand the course instruction. Don't ask questions during class, but if you have the opportunity after the lecture you may thank the professor for letting you observe and ask a question then. In general, don't try to think up random questions just to say something, but if you have a genuine curiosity about something, asking a question after class may give you a better sense of how accessible and approachable the professors are.
Be sure to take notes throughout your visit. Your impressions of the school, and details that you remember may be useful to you during the application process as your write your personal statement essay or answer questions about why you are interested in the school.