Funny you should ask…I just recently wrote an article for gamasutra on this very topic: http://gamasutra.com/blogs/StephenFroeber/20140112/208457/Networking_at_GDC_A_Beginners_Guide_Part_1.php
I hope you find it helpful. I would bring a few CD’s just in case, but hand them out when you have a serious lead…don’t hand them out just because.
Polo and jeans is fine. People wear all sorts of attire, so you won’t be over or under dressed with that.