What size should I use?

Well since winter is here I figure its time to work inside the house. So I figure I will spend the winter building a wiring harness for the whole car. Lights, radio, ignition and everything else but the engine.
The question I have is what gauge wire should I use for all this? Is there a specific size I should use for each or can I use the same size for all? This will be a 12 volt system with either a 318 or 360 in it.
So I need the size for horn, headlights, taillights, parking lights, interior lights, radio, ignition, reverse lights and anything else I might have missed. I want to keep the minimum amount of wire running through this car, Less wire going places less chances of problems.

Thanks
Joker51

Well, belive it or not, if you buy a roll of auto wire from wall mart, and look on the back of the package, you'll see what gauge to use for most interior electrical such as cigarette lighter is 14 gauge, for headlights and other under hood electrical, I'd use 12. I'd use ither 12 for the ign. most of the wiring should have only a positive side. Gonna need a fuse block also, any fuse block will do as long as it's not from a comp controlled car.

joker thats hard to say because its not a across the board thing. this is only something for you to thank about if you use circut brakers you can use smaller wire. a start would be, #1 before the fuse box use 12 ga. wire, #2- after the fuse block use 16 ga. wire, #3-and then 14 ga. to the heavy draw things like the headlights, heater, wipers and ign. if youve got good grounds, good solder joints, all new wire you shouldnt have a problem. :D

Streets I would buy a kit but don't want to spend the 200+ on it. And since I already have 3 fuse boxes laying around from when I did my camaro I figured I would just spend the 50 or so on the wires and sockets and build my own. But I will look around to see if I can find a cheaper one. Maybe I will just yank the one out of a junk car.

CHECK THIS OUT ALL THE WIERING IS 14 GU AGE EXCEPT THE ONES THAT ARE MARKED USED THIS ON THREE DIFERENT RAT RODS NO TRUBLE YET I HOPE IT HELPS

THanks Shaggy