If the school is far, wait and see if your application succeeds. Prepare for the visit by reading about courses and requirements in the catalogue. Perhaps more so than the faculty, the other students provide intellectual stimulation and moral support. If you cannot visit, phone the department, have the secretary connect you to the graduate student lounge, and quiz whoever picks up the phone. You have to sense the vibrations of the place, but trust your own reactions.
Letters go out immediately to the Great and Unacceptable groups.
The Acceptable group in held in reserve because the top applicants are likely to be accepted by several programs and turn down the offer. Then they start with the top of the Acceptable group. This means that if you do not hear from a program, you have not been rejected and are on the backup list. If the program is your top choice and you are under pressure from other programs for a decision, call to find out where you are on the wait list. Rejoice quickly and consider slowly.