Well, This is THE wiring diagram for Gibson's Les Paul. It's available from Gibson's website so I consider it in the public domain. I'll try to explain it to those not familiar with wiring diagrams. From left to right, there two sets of parrallel lines with spring like thingys next to them. They represent the humbucker pickups, sometimes there are four wires (4 conductor) some times two wires (2 conductor). These wires carry the signal, or notes from the strings.
two wires run to four variable resistors, two of these variable resistors have a capacitor attached accross two of the terminals on the variable resistors making them the tone controls. From the tone controls a lead(wire) goes to the output jack. Two other wires go from the pickups to the pickup selector switch (Treble, Rythym, both). This diagram is relatively simple. Below is the wiring diagram for Gibson's Jimmy Page Les Paul which is one of the most complicated wiring diagrams for a Les Paul. Again this is available from the Gibson web site.