Pennsylvania Court Records
Sylvester K. Stevens and Donald H. Kent, County Government and Archives in Pennsylvania (Harrisburg, Pa.: Pennsylvania Historical and Museum Commission, 1947), while a bit dated, explains the responsibilities of the various county offices, with a good description of the county courts.
The prothonotary has been the clerk of the court of common pleas since 1707. Court records here include divorces, naturalizations, peddlers' licenses, registration of attorneys, oaths of county officers, equity, sheriff's sales, juror lists, some tax records, and some civil court records. Other court records are with the clerk of courts.
Among the few published court records for Pennsylvania is Diane E. Greene, Cumberland County, Pennsylvania Quarter Sessions Dockets, 1750'1789 (Baltimore: Clearfield Company, Inc., 2000). Some court record abstracts have been published in various journals, such as The Western Pennsylvania Historical Magazine.
Other courts exist in Pennsylvania, although their jurisdictions are less likely to have genealogical impact. These include the supreme court (1722-present) and superior court (1895-present), with mostly appellate but some original jurisdiction. Federal court records are at the National Archives'Mid-Atlantic Region.