Using android mobile to control arduino

First of all THANKS,
this was the project that I was waiting for.
I do not understand very much the wiring connection, especially the bt connection, my lack.
green wire: pin0 (arduino) - ? (bt)
yellow wire: pin 7 (arduino) - led
black wire: ? (arduino) - resistor - ? (bt)
red wire: ? (arduino) - ? (bt)

and like in a loop I finish with
End of all THANKS