It is very difficult to generalize about the graduate admissions process because graduate schools vary so much. The information in this section is offered with the understanding that some of the schools to which you apply will probably do things differently. I am writing from the graduate admissions office perspective. Things no doubt look a bit different from the applicant's perspective. For an applicant's perspective on what is involved in getting into grad school, click here and learn from David Burrell's experience.
Graduate schools vary a great deal in their organizational structure.
There is, however, usually some centralization of authority for admissions, records, and degree-granting in a graduate school office. At many graduate schools, your application for admission will be reviewed by both your proposed graduate program office and a central graduate school office. This means that you may have to fulfill two different sets of application requirements. It also means that the entire process will take some time, so the earlier you begin it, the better off you will be. If two offices are involved, they will probably use different criteria in evaluating your admissability.