I've seen many books or magazines as standalone apps. You download them from the app store as one single app. When you open it, it's just like reading a book or magazine and you can turn the page and scroll pages at the bottom. Very easy to use, not fancy but simple. You might not be able to zoom it, but on iPad it's fine.
There seems to be a standard framework or tools to allow easy creation for non-developers.
Any free tools out there that anyone might know?