To answer a few of the questions above.

To attend the job fair you have to be a OBAP member. Anyone can be a member, just cost $50, sign up on the website.

Once you are a member you can register for the job fair online.
There are a bunch of different things going on at the convention, all with their own price. When you start to register you will see all the options.
The registration for the job fair is $145, it is good for all 3 days.

They sent an email saying they will have signups for the majors in mid July. Other airlines do not have sign ups.

and you should all wear shorts and a Hawaiian shirt :-)