Census-Online.com - census transcriptions for Lancaster Co.
Interment.net - cemeteries of  Lancaster Co.
Lancaster Co. Cemeteries (over 40 cemeteries here)
Lancaster County, PA Genealogy Forum read and post messages about your ancestors for this county
Lancaster County GenWeb Project collection of online resources for genealogy researchers
Lancaster County Message Board read and post messages with other genealogy researchers of this county
Lancaster County,  Hanover Township,1750 Tax List
Lancaster Co. Census Records
Lancaster Co. 1771 Tax List
The Tombstone Transcription Project - cemeteries for Lancaster Co; PA
US GenWeb Archives for Lancaster County cemeteries, newspapers, wills, military rosters etc recorded online here

Additional Resources

Pennsylvania Newspaper Search enter your ancestor's name to instantly search the world's largest newspaper archive; over 12 million newspaper pages
Pennsylvania Birth Records
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Pennsylvania Death Records