Local law frequently is called "municipal law" because municipalities (also called municipal corporations) pass much local law. Pennsylvania municipalities can be cities, townships, or boroughs, which in turn are assigned "classes" based on their population. Pennsylvania counties also can pass laws, so each Pennsylvanian is subject to the laws of both their municipality and county. For further information, WHYY has a good Explainer on municipalities.
Pennsylvania follows Dillon's Rule, which means that local governments derive their powers from the state and only can exercise powers that the state specifically authorizes them to use. Some Pennsylvania municipalities, however, have adopted home rule charters. Starting in 1951 with Philadelphia, the Commonwealth has transferred some of its authority to home rule municipalities, which means these municipalities can act anywhere except where specifically prohibited by state law. Examples of home rule municipalities include Philadelphia, Pittsburgh, and Norristown.
Local-level statutes typically are called ordinances, and their published compilations are called codes. Home rule municipalities also have a Home Rule Charter, which can be likened to a constitution for the municipality.
Local governments have legal advisors, also called solicitors, to provide legal advice to the government. With the exception of Philadelphia, solicitors' opinions rarely are published, although some may be available on the local government's website.
Pennsylvania's Department of Community & Economic Development has compiled Pennsylvania statutes concerning local laws here.
The Pennsylvania Manual contains extensive information about Pennsylvania's local governments. Local government information is in Section 6 of the Manual.
Local government websites often contain a wealth of information about the county or municipality, such as codes, forms, and how-tos, as well as contact information for government offices and officials. Phone calls may get a better response than an email.
In addition to the local government's website, local codes may be found on one of several websites. (Tip: An internet search for "[municipality name] code" or "[municipality name] ordinances" often is the best bet for finding them.) Local code databases include Municode, General Code: eCode360, and American Legal Publishing.
Historical municipal codes and ordinances may be available through a local library or the Pennsylvania Historical & Museum Commission.
Local newspapers contain coverage of local government activities, including law-making, that may provide insight into why an ordinance was passed and how it has been implemented. Local newspaper coverage is available via Lexis News (Temple Law access) or Temple University's various newspaper databases (Temple University access).
The Municipal Law Reporter (available at Temple via HeinOnline for 1909-1956) and Chrostwaite's Pennsylvania Municipal Law Reporter (available at Temple via HeinOnline for 1956-1962 and in print for 1956-1989; ceased publication 1998) reported Pennsylvania municipal cases.
The City of Philadelphia is Pennsylvania's only first class city, based on its population of over 1 million individuals. Philadelphia was Pennsylvania's first home rule municipality, adopting its Home Rule Charter in 1951. Various Philadelphia resources are listed below.