So sad...

Was going to show you pics of Partnercentric's booth a couple years ago when I worked the show with them. I made a collage but it got deleted.
Anyway, one of the reasons to have a booth is to collect leads, so you will want to have some type of contest so you can collect biz cards. Most affs don't have cards so you'll also want entry forms too. Also most people give away schwag so you'll want to have some type of branded promo item to give away for branding purposes.
I came up the theme and contest for PC's booth a couple years ago. The Theme was "Let PartnerCentric Take the Stress Out of Affiliate Marketing." We gave away little stress relief balls shaped like computers with the PC brand on them and had chair massagers in the booth. We gave away some other stress relief schwag too - can't remember. We also hosted a PC party with the same theme and had a masseuse doing chair massage, played mystical massage music and stuff. It was all VERY cool!
The contest we did was all online, so the lead forms were electronic and the affs entered in their own details so there was no data entry needed after the show to do follow-ups. But the online contest was a pain - had all types of tech problems.
You'll want a backdrop display so you can have signage and also to "keep up with the Joneses" and have your display look as good as or BETTER than your neighbor's.