If you are starting from scratch I would recommend having a database with your inventory and uploading to ThirtyBees using the csv import. There are several book databases available, BookTrakker.com is probably one of the best but has a monthly subscription fee. Bibliopolis.com has a product called Bookhound that can be purchased outright. Abebooks.com has a free product called HomeBase. Or if you, like me, are a glutton for punishment you can build your own using MS Access or FilemakerPro :)
As far as adapting 30bz, I use the product name for the title and all the other bibliographic items, author, publisher, date etc are features. The short description lists all the bibliographic information and basic condition of the book and DJ. The long description has the expanded condition. You can see how it plays out in the front office at LJsBooks.com. I tried using layered navigation but with the number of different authors, publishers and all it just didn't work. I disabled the add to cart buttons on the products featured on the home page and on the category pages because I want people to read the condition description before they purchase the book.
I hope that helps, if you have any questions please feel free to ask.