Originally Posted by Asur
Pretty well anywhere in the side you will find lots of room to put one, but I would suggest Driver side, near the tail gate, easy access when you need it.
Also, easy to send the wires up to the front of the truck, just follow the frame and all the other wires
I have one of the 12 Volt outlets as in the picture. They work great, but they are not waterproof. Make sure you install it under a bed cover or go to a Marine 12v outlet.
Make sure you use a heavier gauge wire for the distance you need to go to get to your battery.