Makey Makey Classic Hookup Guide
jimblom, 
bboyho 
Hardware Overview
Top Side
The Makey Makey is a two-sided circuit board. On the more simple top side, the Makey Makey has six inputs: the up/down/left/right arrow keys, as well as the space bar and mouse left click:
Each of those inputs as well as the very important “Earth bar” are available in the form of what I like to call “alligator-bait” connectors. You'll use the included alligator clip cables to clip right into the hole pairs. This will all be made much more clear in the next section. For now, let's keep summarizing your Makey Makey.
If any key is activated with the "Earth Bar," an associated LED will light up next to the pad.
Back Side
When you flip the board over to the back side, you will notice a mini-B USB connector and POWER LED. The connector is where you will connect the USB cable to a computer. The LED will light up when the board is powered.
You've also got access to 12 more keys via the black female headers:
- W, A, S, D, F, and G on the keyboard side
- up/down/left/right mouse movement and left/right clicks on the mouse side
The bottom header has six additional ground (aka Earth) outputs.
The top header is an expansion/output header. They KEY OUT and MS OUT are connected to the LEDs on the back to indicate whether you're pressing a keyboard or mouse key, respectively. This can be used to connect low-power LEDs and small motors. The RESET will reset the board when connected to ground. There are also pins for power through the 5V and GND. The last two pins (PGD and PGC) are used by the factory to program.
The pins broken out through the black female headers are all available in the form of “jumper-wire” connectors to connect male jumper wires, header pins, stripped wires, or tinned tipped wires.