Most of the better MBA programs prefer you to have a few years' work experience before starting the program. Two or three years ought to be enough. With an accounting degree today, that shouldn't be a problem, because the job market for accountants is better than ever today. I'd recommend taking a job for a few years and then go back for the MBA later.
Go to the library and pick up top business schools rankings books. They have it for BusinessWeek and other publications. It really depends on what you want out of the MBA. The most prestigious are the best of course..but some are better than others in specialty.
You can use the MBA to advance to management in your current field or change careers. It is somewhat flexible.
Btw, you normally need at least 2 years of full-time work experience to get into the top schools. I would suggest working for a couple of years and then apply. The full-time work experience is important because MBA's who go straight from undergrad have a harder time finding jobs due to lack of experience. Good luck! I'm bored and have nothing to do or anywhere to go this evening...any suggestions?