There are several useful Documents under the Volunteer and Budgeting topic pages of the Knowledge Network. You may want to start with:
Managing Volunteers in a City- provides tips on recruitment and training.
City of Roseville, CA’s volunteer handbook and Supervisors’ guide to managing volunteers describe volunteer process including selection.
You may also want to look at the Multnomah County, Oregon case study called “Citizen Budget Advisory Committees Provide Oversight” that provides the volunteer forms, duties, memorandums and recommendations of the committee.
I hope this is helpful,
International City/County Management Association
Knowledge Network Intern