However there was an article back in 2012 at elementary OS’s website about keyboard shortcuts in Luna, I think many people are not aware of these. These shortcuts will also work on the next version of elementary OS, named Freya. I think these shortcuts are extremely useful, using them makes a lot of things quicker and they make your OS more efficient.

⌘+Space App Launcher
Alt+Tab Window Switcher
⇧+Alt+Tab Switch Windows Backwards
⌘+W Window Overview
⌘+A Window Overview (Across All Workspaces)
⌘+Left/Right Switch Workspace
⌘+S Workspace Overview
⌘+0 New Workspace
⇧+⌘+Left/Right Move Window with Workspace
Ctrl+⌘+Left/Right Snap Window to Half of Workspace
Ctrl+⌘+Up/Down Maximize/Unmaximize Window
⌘+L Lock Screen
⌘+Click+Drag Move Window
⌘+Secondary (Right) Click+Drag Resize Window
= Super (Windows or Command key), = Shift

Video about Super shortcuts in elementary OS