Thanks for the suggestions.
Silverraven, I took a look at the link and may try the trial, but it looks a little overwhelming.
Koland, I've only ever used Calibre to convert to epub--never tried any of the management features.
Odiakkoh, I'm using an Excel spreadsheet now. I was thinking of an app to save time--so I could just type in the ASIN to get the information (or scan a barcode for an audiobook CD). It would also give me a book summary, which would be useful.
I had started to use
Book Catalogue for my paper books, and while it would work for audiobooks, the drawback is that it doesn't allow for a "Narrator" field. So I was hoping there might be something out there that's more customizable for audiobooks.