There will be lots of information made available to you in the coming months. Keep an eye out for a facebook page and likely twitter and instagram as well. Once you express interest you should get emails updating you on what's going on. They do want students from all four years and at the upper class levels you would probably be sought after for leadership and maturity. Highlight those aspects of your collegiate experience and you should do well.
As an aside, we have a GC member here who is VERY involved with the closing SPSU chapter which is basically moving over to Kennesaw so she will be a great reference for you. On the other hand, there is an alumna here who will undoubtedly be involved with the colony so be very careful about your p's and q's here on GC.
Good luck!