Set up dev environment on your Mac.
You can create a virtualization solution for cross-platform development on OSX.
Check out my previous post on how to install Windows 8 and developer tools on Mac.
Learn how to build Windows 8 or Windows Phone 8 apps
More beginners’ sessions are available here.
You will learn the ins-and-outs of the Windows platform from iOS developers who are now building Windows apps. Sessions will follow a low-key, interactive format where iOS terms and concepts will be mapped to Windows alternates. You will also get hands-on time to apply what you've learned.
Day 1: • Introduction to the platform and the Windows Store • Design differences between iOS and Windows 8 • Tooling: Visual Studio and Blend • Asynchronous programming • Consuming web services • Advanced UI development with XAML (data binding, templates, and collections) • Ask the Experts panel • InstallFest
Day 2: • Process Lifecycle Management and State Management • Notifications and Live tiles • Bing Maps, SkyDrive, and Microsoft Account integration • C++ for Windows Store Apps • Reusing code with Windows Phone • Hands-on-labs
Port or create apps for Windows 8/Windows Phone 8
Sign up for a free Windows 8 design and developer session here at Generation App.
Check out additional resources below.
Windows 8 for iOS Developers