Here are a bunch of resources to help you get started in building your Windows 8 application!

To get started:

• Get Windows 8: http://windows.microsoft.com/en-US/windows/download-shop
• Create an account at the Windows Dev Center to submit your app: http://msdn.microsoft.com/en-US/windows
• Get the Tools & SDK
• Optional, get free Design Assets

Top developer resources

• Windows 8 Developer Guide
• Windows 8 App Developer Blog
• Windows Store blog
• Windows Store markets
• Windows Dev Center
• Code samples
• Technical Docs
• Channel9

Top UX resources

• Designing UX for apps
• UX guidelines for Windows 8 style apps
• Microsoft Expression Blend Team Blog

Still not enough? Here are some other resources:

• Why Windows 8: http://www.microsoft.com/uk/msdn/windows8/whyw8apps.html
• Getting Started: http://msdn.microsoft.com/en-us/windows/apps/br229512.aspx
• Building Windows 8 Apps Lab: http://www.microsoft.com/en-us/download/details.aspx?id=34619
• Windows 8 Ads in Apps SDK: http://advertising.microsoft.com/windowsadvertising/developer
• Best place to go to for everything else: http://msdn.microsoft.com/en-us/windows/apps/br229516.aspx

If you have built an app and submitted it in the store, post a link in the comments and I will definitely check it out.