Some of the books members try to add with an ISBN number via the Import Books feature we are able to add if the book's information can be found on Amazon. This is done periodically and you will see the requested books appear if you sort your bookshelf by "Date Added to Library" -- that way you will see the newest additions.
However, any book with or without an ISBN can be added manually if you are volunteering to index it. You can email the information to [email protected] and include title, sub-title, author, publisher, publication date, format, # of pages and cover image (scan or photo) along with your request.