The resistor limits the amount of current that can pass through the circuit: if you wire the LEDs to 12 volts directly they just burn up instantly. You can buy the LEDs and the resistor at Radio Shack- there is probably $4 worth of parts there. I tied into the accessory lead for the (+) side and tied the ground side (-) to the front screw that holds the glove box on. The accessory lead is under the top / left fairing cover, inside the black rubber boot; it is buried in there so you have to fish around a bit for it. The (+) lead is a female bullet connector (4mm or 5/32 inch diameter) so you will need a male bullet connector to connect to it. They are readily available at auto supply stores like Auto Zone, etc.
I soldered mine together but you could just crimp all the connections with butt splices and a crimping tool, again readily available at auto supply stores. It is a simple job, just remember that LEDs have polarity and must be wired in the correct direction regarding (+) and (-).
Absolutely nothing bad will happen if you wire it backwards, the LEDs simply will not light. If you are unfamiliar with wiring I suggest temporarily wiring it by holding the wires together with tape (any tape, even Scotch tape) to get it working and then crimp or solder everything later.
Brian
Edited to correct bad data: small white LEDs are reverse voltage limited to 5 volts, at least some of them. Do NOT wire them backwards.
I like it.
I also like to ride at night and have the same problem. I carry my surefire in the box, but it takes up too much room.
I am not much on electrical stuff. Why the resistor? Where did you tie into the ignition? Where did you purchase the LED's?
Thanks