An interactive tutorial, where it will teach you all the basics of Objective C. Great for those who have no experience with C or Objective C
This is more of a technical approach to learning Objective C, but just as informative!
If you know a bit about Objective C, you can try creating your first app! This tutorial will show you exactly what you need to do.
This is the official apple documentation on getting started. It may be a little formal however it includes everything you will need to know and more to create a good app.
This is a great tutorial on how blocks work and how they are used in applications. Take a look because blocks are very important in iOS development.
This is a tutorial that will teach you how to declare delegates and how they are used in iOS development. This is also another very important concept in iOS development.
Create your very own side scrolling shooter! Even provides you with the necessary art and resources to create the game. Very easy to follow, and is a recommended starting point for iOS development just so you can familiarize yourself with the language.
The official documentation for SpriteKit, this will tell you everything you need to know about SpriteKit, but it may be a bit overwhelming for those who have no experience with Objective C.
One of the unique features of developing iOS apps is the storyboard! Learn how to create quick good-looking app with as little coding as possible.
This is a tutorial on how to create animated transitions, to make your app feel more intuitive and visually pleasing. This topic is critical and is very useful when creating apps for iOS, so it is a must read!
Autolayout on Storyboard
This is a two part tutorial on how to utilize auto layout on the storyboard. Create responsive app layouts to make sure your app is always looking great whether the device is horizontal or vertically placed. Be sure you have a good grasp on storyboards before you begin!
This is a wonderful website in which you can view a bunch of iOS user interface mockups and ideas. A great place to look for some inspiration for that new intuitive design of yours!
The official design guide for iOS 7, includes everything you will ever need to know about the design features that iOS 7 provides.
Other Useful References:
This is a quick reference page that shows you the window size of the different iPhone models.
In the Library:
iOS Programming: The Big Nerd Ranch Guide leads you through the essential concepts, tools, and techniques for developing iOS applications. After completing this book, you will have the understanding, the know-how, and the confidence you need to tackle iOS projects of your own.
Your guide to developing solutions on the iPad, iPhone, and other iOS 5 devices and platforms, this comprehensive book provides in-depth code samples and discussions for scenarios that developers face every day.