These guys make this sound very complicated!
True, a Realtor is never a substitute for an attorney, so my advice is limited and I do encourage consulting an attorney or accountant. That said, settling this estate may be fairly simple.
Do you know if mom owned the house or had a mortgage or other loan on the property? Was she involved in any legal matters that may impact the home - liens, judgments, etc? Is the home willed to you exclusively or to you plus others? These are all things that could complicate what I say below, but generally speaking, this is what I think you'll need to do:
Take your mom's original death certificate and will to City Hall's Register of Wills to obtain "Letters of Testementary". Once you have thius document, you will be ready to put the house on the market and put the process of paying Estate Tax in motion. If Estate Tax isn't paid and recorded by the City and State prior to settlement, the title company will hold money from your proceeds at settlement and use it to pay the tax. They will hold MORE than the projected amount due (how much varies by title co). Once the taxes are paid and processed, the State will send a receipt showing a zero balance. After you have this important receipt will the title co. return the balance of proceeds.
Please contact me for further assistance with the sale of your mother's home in 19139; I think I can help make this an easier time for you.
William Festa Realty
3001 S. Sydenham St.
Philadelphia PA 19145
(215) 271-3000 office (ask for me!)
(215) 869-9571 cell