Re: Ask not, what your dojo can do for you..
What is taught in many dojo's is priceless.
You at the very least owe it to yourself and others to keep the facility clean (this is your building, you clean it) and running smoothly. Collecting payments for sensei, answering basic questions for new people. Respecting the dojo and the people in it outside it's walls. Encouraging others to check it out and see what's there ( i don't mean chase them down and beat them up, but if it comes up in conversation ask them if they want to drop by) and to go along with that, KNOWING YOUR DOJO'S ADDRESS AND THE PHONE NUMBER (something that was on one of my first tests = D ). Organizing parties, if that's the kind of thing you do.
Did i miss anything? I'm sure i did, i typed this up pretty fast.