Here are some Windows 8 keyboard shortcuts I found out via the process of trial and error. Some are more useful than others and some are indispensable.

Windows 8 Shortcuts – Using Windows Key 

Very Useful 

Windows Key + S             Start Menu

Windows Key + D             Desktop

Windows Key + C             Charms                 Accesses Settings for current App

Windows Key + Tab        Apps Slider at left side, to change Apps

Quite Useful 

Windows Key + F             Files menu, at right side

Windows Key + X             Useful list of options from Desktop to Programs & Features

Windows Key + M           Minimize current App

Windows Key + P             Project to another screen

Windows Key + I              Settings

Windows Key + U            Accessibility

Windows Key + R             Run – run programs etc

Windows Key + E             Computer window appears

Windows Key + W           Settings

Windows Key + Q            All Apps list appears

Nice to Know

 Windows Key + L              Lock Screen