You may have owned your home for a long time.

If not, you will have a problem as it may take months to retrieve that document from the bank. Make sure you have it ready before deciding to sell. Without it you will not be able to transfer title to the buyer and your sale will stall.
As part of my service I provide a surface title search but, the original if available is preferred.
Often, the buyer’s bank will want a new survey of the property. This is the usually responsibility of the buyer to order and pay for. However, while your house is for sale, prospective buyers may want to get an accurate idea of property boundaries, so if you have a survey or tax map be sure to find it.
Do you have your latest copy of this years tax assessment. Are there any taxes outstanding? A buyer can claim misrepresentation if the true property tax amount is not disclosed.
As part of my service I provide a facsimile from the Assessment Authority however, the original is always best.
If you have it you will need a copy of the certificate that states you own the house and that no one else except your mortgagor makes claim to the property.