The USGenWeb Project has grown rapidly over the past year. Many counties
have posted a considerable amount of data online, including census,
wills, tax, deeds, letters, obituaries, cemeteries, etc. Prior to
starting fieldwork in any US county, you should see how much information
is already available at this source.
You can contribute to this project by dusting off your old reports and
providing local history information, letters, etc.
http://www.usgenweb.net/statelinks-table.html
Bill Adams