General keyboard shortcuts

Alt-Ctrl-L     Locks the screen.
Alt+Down     arrow  Equal to single Click
Alt-F10     maximizes the current window.
Alt-F1         opens the Applications menu, then use the arrow keys to navigate the submenus.
Alt-F2         opens the Run Application dialog box.
Alt-F3         opens the Deskbar Applet (F3 opens the search bar at the bottom of the window).
Alt-F4         closes the current window.
Alt-F5         unmaximizes the current window (if it's maximized, of course).
Alt-F7         followed by arrow keys or mouse movement, adjusts the current window's position.
Alt-F8         resizes the current window.
Alt-F9         minimizes the current window.
Alt-spacebar opens the window menu.
Alt-Tab     moves between open windows.
Ctrl-Alt-Tab moves between open panels on the desktop.
Ctrl+A         Select all (In Documents, Firefox, Nautilus, etc, not Terminal)
Ctrl+C         Copy (In Documents, Firefox, Nautilus, etc, not Terminal)
Ctrl+E         Send To... (Send the current document to an email recipient or remote location, not in terminal)
Ctrl+N         New (Create a new document, not in terminal)
Ctrl+O         Open (Open a document, not in terminal)
Ctrl+P         Print (Print the current document, not in terminal)
Ctrl-Q         closes the current application.
Ctrl+Q         Quit (Quit the application, not in terminal)
Ctrl+S         Save (Save the current document, not in terminal)
Ctrl+V         Paste (In Documents, Firefox, Nautilus, etc, not Terminal)
Ctrl+W         Close (Close the current document, not in terminal)
Ctrl-W         closes the current window.

Alt+Tab         Switch between open programs
Ctrl + Alt + Backspace         Kill X server
Ctrl+Alt+F1         Switch to the first virtual terminal
Ctrl+Alt+F2(F3)(F4)(F5)(F6)         Select the different virtual terminals
Ctrl+Alt+F7         Switch to current terminal session with X
Ctrl+Alt++         Switch to next X resolution (Depends of your X configuration)
Ctrl+Alt+-         Switch to previous X resolution (Depends of your X configuration)
Ctrl + '        use : select all text within ( ) braces
Printscrn         Print sreen

Windows key + m        Switch to Contrast mode of desktop theme
Windows + Mouse        Scroll button    To zoom in and out the screen
Windows + ?            To open 'open Location' Dialogue box
ALT+Mouse Scroll    To make the windows transparent