Yep, what booksusa said.
When you first sign up for Auctiva, all of your active listings should get imported into your list of Active Listings on Auctiva (if they don't all appear after a couple of days, you may need to file a help ticket so that they can give it a kick for you).
Once they close, you can go to Closed Listings, check off the ones you want and then click the Import box at the top and they will get imported into your Saved Listings on Auctiva. Here you can make changes, revise, add pics whatever.
Hope that helps, if not, let us know!
Marcia