Yes, it is advisable to visit business school campus at least once before taking admission because schools will see the interest you show for the school. This is a good thing in the application process- when you will be asked in the essays and interviews “Why you want to attend this school”, you can answer that question the best.
During the campus visit you should attend some classes and see the interaction between students and faculty. You should talk with the students, faculty and alumni of the school know how things work on the campus. You will get an idea about the course, teaching methods, extra-curricular activities and other facilities of the school. You will also come across the culture of the school. You will also come to know about the career opportunities and about the financial assistance offered by the school. This will help you in deciding, whether this is the perfect school for you or not.