You can find volunteers using the Advanced Search tool in CiviCRM. See the Search article. You can search a county in the Address section and select for volunteers in the Volunteer section under Custom. See also the Volunteers article.
See the County Fairs article.
You can record Activities and Notes about volunteers on their respective tabs which can be reached from the View screen. The View screen appears if you select View from Search results or after you save or cancel an Edit.