The following link is a good starting point if you want to learn about how to develop Windows Store Apps: http://msdn.microsoft.com/en-us/windows/apps/br211386.aspx
You'll find hundreds of code samples here: http://code.msdn.microsoft.com/windowsapps
...and here you'll find some tutorials:
http://msdn.microsoft.com/en-US/library/windows/apps/dn631757.aspx
