Since I avoid Office with a passion...
... (overcomplicated, bloated and not user-friendly) I can't speak for O365. I, personally, prefer Pages for its simplicity and ease of use. Almost anything I create in Pages comes out exactly as I designed it when saved, opened and even printed through Microsoft's Office.
Any time you need a book to teach you how to use an app, that app is simply more complex than necessary. Even with WordPress I have two reference books that do more to confuse me than teach me.