From Genealogymagazine.com ...
Etiquette for Courthouse Research, by James Pylant: On the subject of courthouse research, genealogist and humorist Laverne Galeener-Moore advises, "One fact you must be prepared to accept is that the majority of staff members employed in County Clerks' or Recorders' offices hate the very innards of all genealogists. . ." It is true that some clerks just do not want to be "bothered" with researchers, but others have had too many unpleasant experiences with genealogists. This, in turn, colors their opinion of all genealogists who enter their office. To make a personal visit more effective, we suggest the following:
(1) Dress Appropriately. Like it or not, people do judge others by appearance. Make your visit appear professional. "Carry a briefcase," suggests Diane Dieterle. "The clerk will think you are a lawyer, and lawyers get better treatment."
(2) Be Informed. Before you walk through the courthouse doors, know what years the county began keeping births, marriages, deaths, deeds, wills, etc. Consult the most recent edition of The Handy Book For Genealogists (Logan, Utah: Everton Publishers, Inc., 1998).
(3) Be Organized. Have your list ready of names, dates, and the records needed. Do not ask the clerks for "how-to" advice; they are not genealogy specialists.
(4) Be Courteous. Be prepared to pay for high photocopying costs, and do not wait until closing time before asking clerks to make copies. (Some offices will not make any copies 30 to 45 minutes before closing time.) Respect the staff's time, and do not hold them hostage with tales about your ancestors. Several years ago, a clerk told us that what she found most annoying about genealogists are those who must share their rambling family stories. "Oh, I am always hearing about someone's 'Uncle Mac' and his three wives!," she said.