the spout. find the wiring harness that goes to the distributor (there are a bunch of wires that go to a module on the side - the TFI module). put your hand on the wires at the connector on the distributor. now trace them backwards (toward the windshield). maybe 6-8 inches back, you will see that there are two wires that come out of the harness and go to a plastic plug. the plug may have tape on the end. remove tape (if applicable) and pull the little chip connector (spout) out of the end. now your car is ready for timing. dont lose the chip and put it back once done (it keeps the puter from advancing the timing while you time it).
all cars are different. some ping at 10* while others can take 16*. you want to go as far as you can without pinging. for many (me included), i advance til i get pinging at any time while driving. i then back it down a degree or two and try again. i do this till i never hear pinging.
to counteract pinging, one can run higher octane fuel. also, the hotter it is outside (and thus normally, the hotter teh motor runs), the more likely you are to have detonation. e.g., in the winter i run 14- 15*, but in summer, i run 12*. if i leave it at 14 or 15*, it will ping. there are a number of other reasons that one can experience detonation, but those are the big factors on a healthy motor (no carbon build up, EGR working correctly, etc).
good luck. remember, there is not magic number. the only reason i use a light is so that i can tell someone that i run XXX* timing. you have to listen for detonation (see first sentence in my second paragraph) and go from there.