If you're interested in learning Apple's newly announced Swift programming language, Apple is giving you the chance with a free eBook on iTunes.
Swift is capable of creating iOS and OS X apps, and is based on the best aspects of the C and Objective-C programming languages. Many aspects of the Cocoa and Cocoa Touch frameworks structure the Swift language as well. Apple's free eBook gives you a tour of the language, a detailed guide of features, and provides a formal reference of the language. Keep in mind, you will need an iOS device to read the book. Check out the link below to download it free on iTunes and get started.
The Swift Programming Language | iTunes