I've been using calibre for some time now. There isn't a better program for managing one's e-books. Note I said managing, not cataloging. Newcomers to calibre often get tripped up because calibre copies (not moves) your books into its own "library" (folder) with it's own oddball organization structure. People often find that disturbing because they are so used to maintaining their own folder, file structures. If one can let go of that and let calibre have full control over their books, they will find that calibre is far more versatile than the old M$ folder and file system for keeping track of their books. In addition to organizing books, calibre has its own reader, is able to convert e-books to different formats, can load books onto your e-book device, and even copy them to a folder using a folder-filename structure of your choice. Calibre is also highly customizeable and, best of all, free (donations are appreciated but not required). It also has a user forum here.