I am attending college in Fall 2013. Rush week is the week before classes start. I don't need tips on what to do and how to act but how do the frats get your information. Do I give them the info there or do I fill out something ahead of time to let them know I am coming?
I suggest you learn more about each organization and choose who to give your info to. It's always good to go into rush having an idea of who you like more as a guy so you know where to concentrate your efforts to. It's also however a good idea to know where you wouldn't fit in or be wanted (not to sound harsh) so you don't put all your efforts in that group.
If you've been contacted by guys already they should have some of your info already. I won't lie and say we didn't know information of guys prior to rush. Not to scare you or anything but that is part of the process.
You may have to register for recruitment. The Greek Life Office can answer that question. These days, registration for recruitment is often online. There may also be info about it when you attend freshman orientation.