First suggestion is DO NOT eat before going. There are so many companies giving out samples of their product it is crazy. The big dog purveyors even have hospitality kitchens set up and serve food cafeteria style all day long. Also, last year they allowed the public to enter early (9 or 9:30)but only to attend the pizza making competition, the gourmet pizzas were Sun. and Traditional was Mon.(check to see if this holds true this year), but you couldn't leave the making area until the show opened, but thats not all bad since during the competition the pizzas are made one at a time, taken to the judges for sampling and then brought out to the public for consumption, and last year there was barely anybody there from the public to sample. Needless to say I got my fill of many different styles of pizza.
Another thing, take your time. Even though it is a large show with many booths to see, many may not tickle your fancy so don't feel like you have to race through the show, you should be able to cover the whole show in one full day, and then go back and revisit any booths of interest.
Be sure to get show times for the U.S. pizza teams dough tossing exhibition, it's pretty impressive, and there is a Q and A session at the end.
Be sure to talk to Big Dave O. and Tom Lehmann at the test kitchen they are always a fountain of information.
Also, I live in Columbus. So if you have any questions regarding the area just send me an email and I'll try to help you out. Enjoy.