The University’s Admissions Office provides detailed information about all undergraduate courses and the admissions process. You should also pay careful attention to individual college websites and prospectuses. If possible, it is always useful to attend a college or university open day. The next university open days, which will offer you the opportunity to meet members of staff and current students and to visit the department, as well as an introduction to some of Cambridge’s unique resources, will be in the first week of July 2016. More information about these (including how to book) as well as about other opportunities to visit the university and its colleges, can be found here.
As far as the study of the History of Art is concerned, if you have the opportunity to visit significant buildings or art galleries and exhibitions that will help you think more about whether you might like to study the History of Art at degree level. You will also find it useful to explore some of the books listed here.