In an interview with Frank Oddbratt, experienced geek event organizer I learned lots about how to organize your team of volunteers, potential problems and tips.
For conventions there tends to be 3 levels of volunteers. The head organizers, the area heads and what we in Swedish call funtionärer (another word for volunteers). Funktionärer join to help during the event with very little activity prior and after the event. They work in shifts and have time to experience the event as visitors also. The smaller the event the less need there is for multiple levels.
The area heads organize and lead a specific area. They are normally given a budget and do activities before and after the event incl. putting together their team of funktionärer.
The head organizers lead the entire event. They handle budget, venue, contact with government, grand applications etc. They are the ones who set the vision and gets everyone else on board and heading in the same direction.
For more information on how to find people to join the team and tips check out the article at Nerdpunk Magazine: