In the fuse panel on the driver side of the dash, there is a <font color="red"> red <!--color--></font> 15amp fuse that goes to the guage cluster. You can pull that fuse, strip back some of the wire you are using to the guage, and when you put the fuse back in, "sandwitch" the wire in between the fuse and terminal block. Find a good ground near the source to ground it to. That is your ignition source.
For the 12v light source, I tapped into the dimmer roller switch, so it could be dimmed with the rest of the lights. Take the dimmer switch out, and tap into the white wire (I think. Use a light tester to find find the right wire.) Also, find a good ground.
It really isn't very hard. Good luck!