If you get the wiring harness it will be plug and play into the car.
You will have to wire the wiring harness to the stereo though. Best way to do it is solder and heatshrink. If you don't know how, go to Autozone or Kragen, hardware store, or electronic store like Frys and get some butt connectors and a crimp tool and use those. The butt connectors should be the 22-18 or 22-16 variety. This size is typically red color. The numbers are the wire gauge the butt connectors will take. You will need to match up the wires that come off the head unit to the ones on the wiring harness.
If you are not using an external amplifier, there will be 13 wires that you will need to connect on the wiring harness.
Butt connector
Crimper/stripper tool