A few resources to get started learning iOS app development and Swift:
- Treehouse has a great collection of lessons about iOS app development with Swift. If you time it right, the seven-day free trial may be enough to get you started, and especially if you pack a lot into a month or two, $25/month isn’t bad.
- Naturally, Apple has a great getting started guide.
- Big Nerd Ranch is a world-class dev training company based out of Atlanta. This book and this book that they’ve written might be helpful.