A thick religious text similiar in scope to the Bible is going to be a pretty solid choice regardless of which one you choose. The content of those books generalizes quite well over most of human experience.
Besides, once the immediate needs for survival are met, you can develop techniques to improve your life on your own time. Creating works of literature is an altogether different kettle of fish. In the Sermon on the Mount Jesus merely cites the observation that bread isn't sufficient for living.