USEFUL KEYBOARD SHORTCUTS

General keyboard shortcuts

Ctrl+A = Select All (Terminal: Home=move cursor to beginning of line)
Ctrl+C = Copy (Terminal: Kill process)
Ctrl+V = Paste (=Shift+Ins in Terminal: )

Ctrl+N = New
Ctrl+O = Open
Ctrl+S = Save
Ctrl+P = Print

Ctrl+E = Send To...
Ctrl+W = Close
Ctrl+Q = Quit

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 + Alt + Backspace = Kill X server

Alt+Tab = Switch between open programs
Printscrn = Print sreen

Command line / Terminal shortcuts

Ctrl+C = Kill process (else: Copy)
Ctrl+Z = Send process to background
Ctrl+D = Log out from the current terminal. In X, this may log you out after a shuting down the emulator.

Ctrl+A = Home (Move cursor to beginning of line)
Ctrl+E = End (Move cursor to end of line)
Tab = List available commands from typed letters (Ex: type iw and click tab, output = iwconfig iwevent iwgetid iwlist iwpriv iwspy)

Ctrl+U = Delete current line
Ctrl+K = Delete current line from cursor
Ctrl+W = Delete word before cursor in terminal (else: Close the current document)

Arrows up and down = Browse command history
Ctrl+R = History search (Finds the last command matching the letters you type)

Shift+PageUp / PageDown = Scroll terminal output
Ctrl+L = Clears terminal output
Shift+insert = Paste

Misc

Mousewheel click or 3rd mouse button = Paste selected text (Select any text in any window and paste where you want. Terminal / Firefox / Gnome apps)

Make gimp shortcut keys like photoshop:
http://epierce.freeshell.org/gimp/gimp_ps.php

HOWTO: Multimedia Keys by piedamaro
http://ubuntuforums.org/showthread.php?t=27039

HOWTO : create a custom shortcut (With keybinding) by frodon
http://www.ubuntuforums.org/showthread.php?t=42404