If it works the same way as most schools in the southeast you just need to register for rush, attend as many events as possible at the houses you're interested in, and meet as many brothers as possible in those houses. That's about it.
It looks like at UGA if you haven't already received a formal bid by August 13th you have to participate in the house tour days and visit all houses. If you don't houses aren't supposed to bid you or they can be sanctioned it looks like.
You can register and read the procedure here
http://www.uga.edu/ifc/rush/index.html