you might want to look into making epub files ; this is the new standard format, specifically designed for ebooks, very powerful and flexible. if can be read natively on the sony already and soon on more devices, is automatically converted to mobipocket format by the mobi desktop app, and can be trivially converted to other formats as well. overall it means less work when creating ebooks.
you can find out about epub here and also i think there are plenty of people on this site who would be willing to help you out with ebook creation / conversion, maybe in exchange for a free copy of the book.
