Have you checked your library to see whether you can borrow ebooks? Overdrive is one of the largest providers of ebooks to public libraries. I have mentioned them before, but what's new is they have developed their own app to allow downloading straight to a mobile device, no need to download a book to your computer first. Libraries would love to be providing their own books as ebooks, with their own decisions on access, and the ability to put the ebooks into their own catalogues..But they aren't in the position to do this yet. Overdrive, and other ebook vendors like EBL and ebrary are here in the meantime
Watch the video below for good instructions on downloading a book to your iOS Apple, or other device including your PC. Just replace the "Orange County Library System", who kindly made this video, with the name of your library. Many libraries are signed up to Overdrive, go check if out if your local library is signed up.