there is two different easy ways to wire the reverse camera.
first off there is an RCA cable from the camera that will run up to the pioneer and just plug in,
then you need to decide if you want the camera on all the time (some radios can have the camera selected as a source so you can keep an eye on what your towing)
if you want it on all the time, then run the reverse wire all the way to the back along with a ACC wire (red from the radio), connect the acc wire to the cameras power wire, and the reverse wire to the trigger wire at the reverse light itself
if you only want the camera on when in reverse, then just run the cameras power wires over to the reverse light, positive to positive, and negative to the lights negative trigger wire, you will also need to run the radios reverse wire back to that same trigger wire.