I went to business school straight after college. On top of good academics, what you'll need are 1) good, relevant internship experiences that will help you understand what you want in your career, as well as 2) strong extra-curricular involvement (community service, clubs and societies, etc) to show that you are a well-rounded individual with interests, passion and leadership experiences outside of school.
Most people get these (understand career goal; leadership experiences and passion) via work experience, but in my experience that's not the only way.