I can only speak to OBAP in 2014, but I recommend having a individualized resume for each airline with whom you are speaking. e.g. "Objective: Career pilot opportunity at Delta Air Lines!" (note Delta makes Air Lines two words). Plus have a few more 'generic' ones just in case you run across someone unexpected. Almost everyone was in their interview suit. The one guy who wasn't really stuck out like a sore thumb - not good.

They will take your resume, and review it with you / mark it up, then probably ask you a few questions about it/you. Then give you a chance to ask any questions of them. Have a few genuine things you want to know at the ready, but make it good. Delta was pretty low key, as was FedEx. UPS didn't take resumes. The United Captain spent more time trying to convince me to come to United, rather than ask me anything - but that might have been just him. Pretty much everyone was low-key except American. They did a mini-interview, complete with a short TMAAT. Expect maybe 10 minutes of their time. Have your game face on, and take advantage of the other guys/gals you will be standing around with - meaning talk to them and network a little. If you have time, and they have any social events after hours, supposedly that's where the real money is made... Don't make a fool of yourself and get sloppy drunk on the free booze.

Once they are done, they will stick your resume in a big pile with everyone else's, telling you that you get an extra point on your application score for showing up. I'm honestly not sure how much the job fair really helped me get hired at Delta, but if nothing else, it gives you a chance to practice some, and get a few questions answered.

Good Luck!