I haven't had my interview yet but original means the official form/document you were issued. You sent in photocopies of certain items, so at the interview they want to see these things. To 1. make sure you have them in your possession and they belong to you 2. Examine them to make sure they are legit.
You would need to take in your birth certificate (26 years old and ripped up is not a problem as long as it can be read) and your sponsor's/petitioner's
Your passport, your petitioner's proof of citizenship if naturalized
Any I.Ds you copied and sent in with your applications
Marriage certificate if you're filing through marriage (I assume you are, based on section & thread you're posting on)
W-2s, Earning slips etc etc. Basically anything you made a copy of to send to them, they'll need the original