Bring two pens-just in case. Get some rest. Get a good night's sleep so you're rested and energized for the fair. Do your homework. Check out the websites of the participating companies so you're familiar with them and what they are looking for.
Career fairs attract hundreds, sometimes thousands of people.
Start in the back. Many people get stuck in the stampede at the front. Make your way to the back where there are representatives waiting for someone to appear. Pick up literature - and a business card. Otherwise your arm will ache carrying around all that stuff.