I personally have an Atlas book on basic wiring which shows some of their switches and how to wire for DC operation. I think most here will not recommend the Atlas components, but I have some and they do work. You can also get small numbers of single-pole single-throw (on/off), momentary, and double-pole double-throw toggle switches at Radio Shack. For larger quantities, try mail-order.
One relevant question here is: will you be using DC or DCC? DCC wiring will be more straight-forward, since DC blocks are not needed. The lighting circuits above are also made obsolete by the DCC decoders in the engines. One caution: decoders will blow low-voltage bulbs since they apply full (14V) track voltage to the bulbs. Resistors or higher-voltage bulbs are needed.
Two books come to mind on wiring. One is Andy Sperandeo’s “Easy Model Railroad Wiring” which you can order from www.kalmbach.com another oldie but goodie is "How to Wire Your Model Railroad by Linn Westcott. It’s out of print but can be found if you look hard enough. Most of my blocks are standard wiring and i use DPDT on/off/on switches from http://www.partsexpress.com/
You can also order the switches from Mouser, Digi-key, Jamesco, and Radio Shack to name a few.
.(I’m going to have to rewire the entire layout when I go to DCC…Wish me luck, because i’m gonna need it …I love train detection circuits and I think the DCC is gonna really screw them up.)
Wiring your layout for signaling is pretty basic…red can mean an absolute “Stop”, “Stop and proceed at restricted speed,” or “stop and then proceed” …it all depends on the train movement within that division of any particular railroad and what the train timetable / rulebook indicates what the engineer is to do for that particular block signal.
Yellow usually means to slow down to a restricted speed (like a train taking a siding or a crossover for instance) or tells the engineer to start slowing the train because there is another train on the same track in the proceeding block.
Green usually means “go.” An all-clear to the next block ahead indication.
Check out this webpage. it explains the different types of signalling ( ABS, CTC, ect. ) and signaling basics.
I use the Dallee system for my train control. They are at www.dallee.com I find that they have some really easy to install circuits. The webpage below&