You can get the basic four pin trailer hookup using a T-One adapter that plugs into your wiring behind the back bumper.
The four wires are for:
You will probably also have to switch to a heavy duty flasher for the turn signals.
To get the other three pins (including brakes) you need:
Black wire - constant 12 volts to power the trailer or trailer battery
Blue wire - trailer brake activation
Purple wire - backup lights
This site has some useful diagrams. http://www.etrailer.com/faq-wiring.aspx