Invest in a spray water bottle and a carpet remnant. You'll benefit by having them, as they will aid you in grooming your rabbits. Very simple to do, and relatively cheap to get. I have a door mat from Wal Mart that I paid all of $5 for and I still use it from time to time with my rabbits. I think I coughed up just short of $5 for the spray bottle which I tote to rabbit shows every time out, too.
Mix and mingle with breeders, not only NZ and FG breeders, but others as well. Watch as many breeds being judged as you can, and see if there are any other breeds out there which strike you as interesting. More showroom breeders than you realize got their bread-and-butter rabbits after attending their first show with other breeds.
If you haven't already done so, pick up a couple of carriers. They don't have to be elaborate, just functional. Another "must have" is a copy of the ARBA Standard of Perfection.
Go there with the full intention to learn and have fun doing so. There will likely be the preoccupied breeder or 2 who won't seem enthused in getting to know you. Spend time with the ones who will mix with you and glean as much knowledge as you can from them. That said, beware of the breeders who are overly friendly to the point that they're trying to pimp their culls on you. ALWAYS look over pedigrees of rabbits that you're considering buying at a show.
Bring a couple of camp chairs. Again, relatively easy and inexpensive to get, but it will help you to relax when you need to take a breather. Do yourself and everyone a favor, though. Set your chair(s) up on the outer area of the showroom, not in the middle of it. Nothing is more annoying to other breeders than having to haul multiple rabbits to/from the show table and being forced to wade around folks' portable living rooms in the process.
Make a list of things you need around your rabbitry and take that with you. There will likely be an equipment dealer who will be peddling all kinds of equipment ranging from feeders, water crocks, nest boxes, carriers, and tattoo equipment, all the way up to things you never thought existed. You know what your primary needs are and what you can afford to spend better than anyone else, but buying them at the shows will save you bookoos of cash versus ordering them online and having them shipped.
