HP Scanjet 7650

1. I am scanning documents and saving them as PDF files. Once saved
and the file is closed, how can I add additional scanned documents/
files to the existing saved file? Does the HP Director software have
that capability?

2. If that cannot be done, can Paperport be used as a software for
scanning, and if so, does anyone know how to set it up with this
scanner?

3. When a document jams, what is the best way to deal with that so the
entire project does not have to be rescanned?

Thank you.