Census-Online.com - census transcriptions for Philadelphia Co.
Genealogy Trails - Philadelphia County has online databases
Interment.net - cemeteries of  Philadelphia Co.
Philadelphia County GenWeb Project collection of online resources for genealogy researchers
Philadelphia County Message Board read and post messages with other genealogy researchers of this county
Philadelphia National Cemetery - Philadelphia County
Philadelphia County, PA Genealogy Forum read and post messages about your ancestors for this county
Philadelphia Co. Landholders 1734
The Tombstone Transcription Project - cemeteries for Philadelphia Co; PA
US GenWeb Archives for Philadelphia County cemeteries, newspapers, wills, military rosters etc recorded online here
1734 Philadelphia County Tax List

Additional Resources

Pennsylvania Obituaries enter your Pennsylvania ancestor's name to search obituaries in over 75 million newspaper pages
Pennsylvania Birth Records
Pennsylvania Marriage Records
Pennsylvania Divorce Records
Pennsylvania Death Records