I've been lurking here a bit and a few times it has come up that either a PDF is unreadable because they didn't convert it nicely, or that an external link is offered because you can't upload a non PDF file.
Well in the following posts I'll share with you how I make nice PDFs out of .epub, .mobi and .azw(3) files using Calibre (get it here
http://download.calibre-ebook.com,
MAKE SURE TO GET VERSION 2.13, later versions have a minor bug that will still work, but without numbers at the end of pages) and I'll share with you Ethics by Plato converted from an .azw file as an example (don't worry, whatever the input format the output will be just like this)