Leo Laporte's pick on MacBreak Weekly 405 is Apple's reference guide for the new Swift programming language. Swift was announced at Apple's keynote address at WWDC 2014, and is a language for creating iOS and OS X apps. It builds on the best of C and Objective-C, and is designed to make programming easier and more flexible for developers.
The reference guide posted by Apple includes a tour of the language, details about each language feature, and more. It's available to everyone as a free iBook in the iTunes store, but if you're a developer you could get the new XCode 6 beta to try Swift yourself.
For more on the Swift programming language, check out MacBreak Weekly episode 405.