I'm a third year applying right now for MBA programs, though I'm only planning to do one year. You don't need any specific accounting/finance background to apply for biz school -- however, you do need to take the GMAT. It's a joke but covers some random geometry and stuff you won't have seen in a while, so take a week or two to study and then take it.
I'm mostly looking at programs that will allow me to do a one year MBA as a med student (essentially a transfer MD/MBA), so I'm not sure about two year programs -- but the programs I spoke with stated that there wasn't a "special" app but simply to apply and make it clear that I was a med student. They do give some special consideration as far as work experience and etc goes to med students since they don't expect you to have had the same amount of real-world work experience.
Good luck and post or PM me if you have any questions.