Just a little documentation for easy access.
Raspberry Pi GPIO Pinout
Raspberry Pi GPIO PinoutNOTE1: The Raspberry Pi is a 3.3V device
NOTE2: The GPIO pins are unbuffered and unprotected, so if you short something out, you could fry your whole Pi, so be careful!
As with Revision 2 of the Rasberry Pi, there are some changes to the GPIO connector. Make sure you use the correct diagram for your board
Raspberry Pi Version 1
Raspberry Pi Revision 2
Raspberry Pi B+