I'm not saying they're completely useless, but if iOS development is the goal, then I see no point in learning how to use a version that is quite a few years old and no longer used. In a worst case scenario, get some iOS 7 books... I'd not go any older than that. Ideally, you'd want to pick up iOS 8 and maybe even their new programming language called Swift ( Objective-C is still a very valid choice and there are plenty of articles / examples using it, but Swift is gaining ground... it will eventually be the default language of choice; that might be in 5 years from now, maybe more, but that's where Apple is heading to ).