You can import the data from isbndb.com - if you know how to import XML.
Take a look at LibraryThing.com. This is an online system for inventorying books. For a small fee ($25) you get a lifetime membership and can inventory as many books as you want (I have over 4000 inventoried there.)
You could then export that inventory to either a CSV or tab-delimited file, import it into Excel for tweaking, then bring it into an FMPro freeware solution like Lending Library or Inventory (or even Music Library), modifying any of those to serve your needs before the import.
LibraryThing also sells a cheap barcode scanner ($15) that does the job nicely.
See http://www.librarything.com/tools for details on the scanner, import/export options, etc.