cell phone in the car. get dress shoes. its one of the first things that they notice. have a list of questions that you would like answered. Take notes but ask if its ok if you take notes. I would say take a copy of your resume but im guessing you dont have that available since you have no job history or anything.
BE yourself! This is a great opportunity. Even if its just interview experience. That is a very valuable thing. I know people who dont know a damn thing about what I do that got a job because of how well they interviewed.
One last thing. thank them for their time as you end. If at all possible follow up the next day again. by email or by phone etc.