Land records are usually held by the county in which the property is located. These records can generally be found in the county clerk's office or in the county recorder's office.  In most cases, the land records have been microfilmed.  If you can not visit the specific county office many times you can find the microfilmed land records in the Family History Library Catalog and then you can rent them at your local FHL.

Start by tracing back from the current property deed. From this deed, get the name of the person(s) from whom the property was bought, the date, and the volume and page numbers where the deed transaction is recorded.

The person who sold the property is called the Grantor.
The person who bought the property is called the Grantee.

After you have obtained a copy of the deed, record the property description and the names of any other individuals mentioned.  Be sure to look out for changes in the property description.  Sometimes, only a part of the peice of property may have been sold.   And, also look for a woman's change of name due to marriage.

Next, look up the name of the Grantor on this deed, in the Grantee's index. You need to find out the name of the person whom he bought the property from, that he later sold.  There are sometimes transfer by means other than a sale - it could happen as part of a will or gift. 

Deeds often include references to court cases.  Usually, they refer to the probate court approval of the sale fo the property by the executor of the estate or the judgment in a lawsuit and the subsequent sale of the individual's property by the court appointed commissioner. 

In many cases the owners of the home are not the residents.  It is important to search the City Directories to find out who occupied the property.  Many people rented homes, especially in the cities.

Now, just repeat the process again and again until you have a complete chain of title.  All land titles can trace back to the English, French, Spanish, Dutch, or Swedish crowns. Many in Pennsylvania trace back to a direct grant of land from one of these monarchs to William Penn. While others can trace back to the sale or free transfer to people by the U.S. Government, which got the property by treaty from the English, Spanish, or French crowns.