Well the first thing you need is a decent fused power source, the battery works fine...just put the fuse as close to the terminal as possible in case the wire chafes on something.
This power source will be used to power the lights, so you'll need to attatch it to one of the pins of the switched side. The other terminal of the switched side needs to be attatched to the load. I'd recomend powering the bumper lights with one relay, and the windshield lights with another.
Once the switched side is hooked up, you need to make the control side work. This is the side with the magenitc coil that turns the switched side on. you'll need to decide if you want the lights to work with the key on, or the lights on, or something else. I suggest you turn them on with the key, so go under the dash to the ignition switch, and find a wire that's powered with key on power.
You'll want to splice into this, and run it to your switch, then run a wire from the switch to one of the terminals of the control side of the relay. The other terminal of the control side needs to be connected to ground so that the coil will energize and close the switched side.
You can run the control sides of both relays with one switch, but I recomend that you use a seperate switched side power source for each, to avoid overloading the power wires.
hope this helps...sorry it's a novel.