For sure stick around and marshal the race you are supposed to. Locally I have seen way to many people to cool to marshal and for some reason you get stuck with no one around!
Also when you are on a drivers stand and there is not much room. Don't try and muscle your way right next to me and then rub me the whole race. Nothing can screw up a run more than that!
Personal Space!
It's a scary thing when you are first starting. Take a new guy under your wings and help them out. You never know when that person will be there to help you!