Minimize all your open windows with Windows key + M
Snap one window to exactly half of your screen with Windows key + either of the side arrow keys, and magically snap a second window side-by-side for easy multitasking.

Need one more window? Press Windows key + the “up” arrow to snap a third.
Open Cortana* in listening (voice-command) mode with Windows key + Shift + C

Open Settings with Windows Key + I

Open the first item you have pinned on the Taskbar with Windows Key + T, then use arrow keys to move between other pinned apps

Open the Action Center to view your notifications with Windows Key + A

Head over here for a full list of keyboard shortcuts, and have a great week!
*Cortana available in select markets