Calibre is a software package every writer should have.  Download it for free (though you can offer an optional donation) and just let it load itself.  It lets you convert book files into formats that can be copied onto all e-readers, including Kindle, Nook, Sony, Kobo.  Conversion is as easy as clicking on a couple of buttons.  It works.

Even if you don’t plan to publish your book as an e-book, Calibre is essential, because there are hundreds (thousands???) of book reviewers out there, many of which allow you to send them e-files.

Alan Zendell