M.F.A. programs vary in structure (e.g., the program at Boston University has a global travel component, and some programs have a larger literature component), but for the most part they’re centered around the writing workshop — the members of the program meet every week to read and critique each other’s work, with a professional writer as workshop leader. Some programs have requirements along more academic lines; others try to keep the writer as free as possible to do his or her writing.
Though the M.F.A. is the standard, there are some M.A. programs in creative writing, which, at least in the past, were considered to be less “terminal” than the M.F.A. Several Ph.D. programs in English now offer a creative dissertation option.