Here is the diagram from my '660's manual. Your manual should have a similar diagram.
The best way is to take the documents I provided you and the manual for your head unit and sit down and draw your OWN diagram, get it all out on paper first (took me five minutes). THEN go to the car and make your connections between the harness you bought and the head unit you bought.

See the line below: "Join the same color wires together"???? That is sometimes WRONG. THIS is why you calmly sit down and make a diagram and figure out what color wire goes to what color wire!