Have you checked out the threads concerning chapter stores? If you submit your logo, in the proper sizes, you can have stickers, shirts, and numerous other items available to your members. Check out www.cafepress.com . That's where a number of chapters have their stores. Or check out www.cafepress.com/hpdrifters . That's the store for the High Plains Chapter. I can answer a lot of your questions about the place, since I set up our store and continue to maintain it. You have nothing to keep on hand, no cash outlay and people can order what they want...as they want. PM me or email me if you have any questions.
Also..as mil1ion said... get the president and the group formed, decide if you want to make a profit, set up a proper bank account. I made my store NON-profit to simplify taxes, etc.