Yes, wear the full suit. Also if you can wear a suit that is not black. Everyone wears a black suit, try grey, you'll stand out. You can bring anything you want but you shouldnt need anything. You'll get some papers to fill out while you are there, and get a NSU portfolio thing, at least we did last year. Good luck, I'm going to try to stop in and say hello to the interviewees. Be sure to be honest, friendly, and enjoy it.
Also be sure to ask any questions you have to your tour guides and the students eating lunch with you. They will answer honestly and give you the best advice they can, so dont be afraid to ask.
Good Luck all!