I suggest you check out this book
. Although it is for connecting other sensors to the NXT (the opposite of what you are trying to do) it does detail pretty much how each sensor works.
I recommend that you also check out the NXT Hardware Developer Kit
As simple as it gets. The black and white wires of the NXT cable are connected to a momentary SPST switch, just a standard digital input.
Analog input. The green wire needs 4.3v (5v?) to power the sensor. The white wire is the analog output. black and red are ground. The yellow wire appears to turn the LED on and off.
Appears to be analog output. Green for power. Black and red for ground. Not sure what the yellow and blue wires do.
C sensor. Green for power. White appears to be power as well
.Black and red for ground. Yellow for SCL. Blue for SDA.
That's all I could interpret from the Extreme NXT book, and from the HDK.