bookstore program in visual basic

I am a student in Information Systems. I am in the first half of a semester in Visual Basic. We have an assignment to development an application that will allow students to go to the bookstore and purchase 5 types of books, add them to a shopping cart and once they have finished, the program should calculate total including discounts.Any help would be appreciated. I feel a little intimidated by this project, sometimes the teacher goes so fast and the shopping cart thing has me a little perplexed. My teacher is good I think its me that does not seem to grasp Visual Basic as fast as she expects. Any ideas would be a big help. Like where to start Sincerely Jamie