As much as Windows 8 Metro is a touch first UI we have not forgotten about the keyboard ninjas out there. Here are some handy shortcuts you can download a PDF of all the shortcuts here.

Charms

Win+C: All charms
Win+Q: Search charm
Win+H: Share charm
Win: Start charm
Win+K: Devices charm
Win+I: Settings charm

 

Search

Win+Q: Search apps
(tip: an even easier way to search apps is to just begin typing from the Start screen)
Win+W: Search settings
Win+F: Search files

 

Apps (Metro)

Win+Z: Get to app options
Win+.: Snap app to the left
Win+Shift+.: Snap app to the right
Alt+F4: Close an app

 

Desktop

Win+D: Open Desktop
Win+,: Peek at desktop
Win+B: Back to desktop

 

Other

Win+X: Open system utility settings menu
Win+PrntScrn: Take screenshot and save to Pictures
Win+Tab: Open switch list
Win+T: Preview open windows in taskbar
Win+U: Open Ease of Access Centre
Win+Spacebar: Switch language and keyboard
Win+Enter: Open Windows Narrator

 

Keyboard shortcuts for previous versions of Windows - http://support.microsoft.com/kb/126449