Nothing very exotic planned here, just some tips on how I wired things.
The track was wired with simple 16-3 outdoor extension cord. Black and white to the rails, and the green reserved A central distribution point (to be hidden under a Mail Pouch barn) is located near the center of the garden and is fed via conduit from the "Acme Power Plant in a Box." It's basically a couple of step-down transformers and ex-electronic device chargers to give me an assortment of AC and DC voltages. The wires from this terminate in 8-prong connectors which mate with connectors in a way-side junction box.
The feeds to the rails were done in several different methods. Tried drilling and tapping the rail to accommodate 4-40 machine screws and crimp-on terminals on the wire (center). Didn't work quite as I had planned, a 3-48 screw probably would have been better. Tried soldering the 16 gauge wire to the web of the rail. That's OK, except that the ties melt about 20 degrees before the solder! (left) Wound up drilling a small hole in the rail, running the wire through, crimping it tight around the base with pliers and soldering it -- after the ties have been moved aside. (right)
Some of the rail joints were also soldered, particularly those in the concrete that will eventually become Front Street. Otherwise just used the as-supplied Aristo joiners with copious amounts of conductive grease. In some cases replaced with Aristo screws with stainless 2-56 cap screws (visible in center photo.) Used Hillman rail clamps on the switches.
Wiring for buildings, signals, etc. is 22 gauge, 4 pair cable used for computer wiring. There's a loop that more or less follows the rail, and two pair of this will be used for the signals, and the other pairs for lights at passenger stops and switch stand lamps if I ever get the energy to tackle those. Other wiring feeds parallel the track-current wiring. All is in either conduit, plastic pipe, short chunks of garden hose and/or split loom. I realize not all of this is shovel or varmint-proof, but we'll see what happens. Telco punch-down blocks were used for connections. (Mistake! They lose spring tension!)
Hopefully building lighting will be done with LEDs controlled by a couple of 556 timer chips. The buildings will probably all come in for the winter, so they'll also need to have some plug and socket work done on the wiring. (McMaster-Carr is a great source for these.)
Note: I put interior lights in about half of the buildings, and others have exterior lighting. As it turns out, I don't run at night very much, so that was kind of an exercise in futility.
BUT repeat after me .... You can never have enough conduit. The wiring has been the main source of problems as the years have progressed. Not that it's been chewed through, but the lack of conduit runs makes it difficult to trace things when you go trouble-shooting.
So...plan where you 'think' buildings might be placed, and track switches might need power, or you might want magnetic reed switches...then run conduit. Then look at it again. And again. In this case, more is definitely better! Don't forget the pull strings!
And while you're at it, how about an AC run so you can plug in power tools as needed? And, how are you going to water your 'garden'? Maybe something to carry water to strategically-placed sprinkler heads?