I have never upgraded iOS before and this is first time I would be doing. My current iOS version is 8.0.4(I guess) and want to upgrade to latest 8.x version(if possible) otherwise the default 9.x version as it's showing.
I want to know how can I take a restorable backup first on my Mac before going to upgrade? I am not so concerned about apps. My main concerns are books(Pdfs,epubs) that I open in iBooks app. Those app have not been bought within iBooks.
Is there anyway to take backup of books before I go for upgrade?