Leave it to the military haha. The Academy notifies the source of your nomination before they contact you, so a lot of people get a call from their Senator or Congressman.
It's different for everyone, but based on trends I think you could count on a call first from a senator or representative if they nominated you. I don't the President or VP do calls though
After that, around this time of year I think they're actually pretty good about the mail. So maybe letter before status. I only say that because they wait a week to change your online status so congresspeople have a chance to tell their appointees personally.