First question - Does your town have a Comprehensive Plan? If so, how old is it and how closely has it been followed? Most states' enabling legislation on planning and zoning requires that a Comprehensive Plan be prepared. It doesn't have to be detailed down to the block level, but you need to figure out what you want your town to "look like", i.e., where do you want the residential, the commercial, the industrial. Don't worry too much about what is already there, those uses can be "grandfathered in" when you write the new zoning ordinance.
The American Planning Association has some very good publication that could help your group in their task. Good Luck!
No, we don't have a comprehensive plan. I'm assuming that the commission will have to come up with one (wow, are we suffering the effects of the 20-year reign of an incompetent buffoon of a mayor!!), although we cannot afford to retain a consultant. I'm trying to get copies of other towns' plans and codes, to give us something to emulate.