You can also think of making a web app of it with a cache manifest file. The cache manifest file will list all the html pages and other assets connected to the pages. When the person downloads the first file, the line: <html manifest=” app_name.manifest”> links to that page and downloads all the resources to the device. Then it could be read offline. If you make changes to any of those pages later, you change the app manifest file contents, then the page on the device will read it, upload the changed pages, and it'll work offline again, with the new pages. I would give a link to an article I wrote on it, but I'm not sure it would be spamming. So just look up "offline web app" or "cache manifest" and you should get some articles to try out.
I suggest this route only if there aren't many pages or other assets. Also, being html, the text would reflow, keeping it easy to read in the device.