Hello, from a fellow New Hampshire rookie team! Looking forward to competing with you guys at GSR!
Most teams purchase a button maker to make their own buttons, traditional buttons have the team logo, number, or name, but are very representative of the team and their image so when other people see them, they know exactly who they came from. Any size from 2"-3" in the norm. I would recommend making anywhere from 300-500 buttons per regional/event.
Good luck, see you in Manchester!
http://www.buttonbiz.com/button-maker.htm