BookCAT is discontinued. BookCAT is a powerful book collector database program which will help you catalog a book collection of any size. BookCAT is used by book-lovers, schools, churches, clubs, and business libraries.
BookCat offers several ways to enter books--you can type in author, title, and so on by hand, or you can enter the ISBN number and search online for information. The interface to accomplish this is powerful, but non-intuitive, a statement which more-or-less sums up the program. First, you enter a whole bunch of ISBNs (you can do it one-by-one, but it's more efficient to do this in batch). Then, you have the entire batch looked up, and see which ones can be found in BookCat's rather extensive and impressive list of sources (Amazon, Barnes and Noble, the Library of Congresss, and others). Then, given this list, you can choose which ones to actually enter into the database. You can also remove from the list all those not found, and so on. The ISBN lookup, if successful (and the success is based on the online databases, not on BookCat per se) can fill in a lot of data for you, even downloading a cover graphic.