[freightshaker]

Simple as possible is 30 & 87 is the heavy load lead that will power the lights. A relay is really just a heavy duty switch that stands in for a lighter, weaker switch. It requires only about .5amp (500ma) to work but can switch 30 amp loads (or more). When you complete the circuit between 85 and 86 with a low amp current this causes a electromagnet to complete the circuit between 30 and 87.
Generally the terminals are like an intersection. North & South will be the load wires & the East/West with be the switched that will complete the load circuit (N&S). Terminal 30 goes to your battery (I HIGHLY recommend a fuse between the relay & battery) or to the fused accessory leads in either the bucket or under the seat) 87 goes to your lights.
85 & 86 one will be ground/hot (either can be hot/ground, works either way) from your trigger source, if you have a 1600 use the blue with yellow tracer wire in the bucket, the 900 has this wire also but it's under the front of the tank near the neck. As for the trigger, it can be any wire that you want to power off of, even the horn but then the lights would only work then you honk