There is obviously WAY more sorority recruitment advice here than fraternity advice, but if you poke around there fraternity advice forum, you should be able to find some stuff.
One thing that jumps out at me is that you want to join before you have even met them: remember that this is a two-way process. You have to decide if you like them, and if they are a good fit for you just as much as they are deciding the same about you.
Hybrid Mode
