- The Big Nerd Ranch blog has several posts on Swift. - http://www.bignerdranch.com/blog/categories/swift.html
- Apple's Swift blog is another resource I've started to reference. - https://developer.apple.com/swift/blog/
- NSHipster has a section on Swift at the bottom of the page. - http://nshipster.com/
- Erica Sadun's blog has several posts on Swift. - http://ericasadun.com/category/swift/
- Follow Christ Lattner, creator of Swift, on the Apple's developer forums. - https://devforums.apple.com/people/ChrisLattner
- Github's Swift style guide. - https://github.com/github/swift-style-guide
- Apple's Swift Resources
- Apple's "The Swift Programming Language" (iBooks)
- Apple's "Using Swift with Cocoa and Objective-C"" (iBooks)
- WWDC 2014 has several presentation on Swift - WWDC 2014
- Apple's Swift programming language document revision history. - Swift Revision History
- SwiftInFlux - ksm keeping track of changes to Swift with each beta release.