Jeff, first, digital requires less wiring. No individual wires to turnout activation switches etc. The track carries the digital data to the signals, turnout decoders, and or the M83, or M84 decoders. Only the wires to the latter two from the track, or other power supply. Those decoders connect together with plugs on the sides.
I suggest the Marklin English digital book 03091. You'll get plenty of input from others too about the wire gauge and lengths, etc.
Of course neatness is important and the shortest possible run is best. The longer the distance, the heavier the gauge of wire.
If you get into feedback modules for automation operations, wiring is needed for the S88 modules from the contact tracks or reed switches, but only one from each. You want to try to locate accessory decoders as close to the items as possible.