Lighting provides another component of realism and is one of the best ways to make models look more lifelike.
For the structures (buildings) I used small LEDs, which I bought from Deeco Electronics, you can choose from various colors available.
Make sure your LEDs can handle the voltage from the power source; otherwise these will burn out quickly unless you put a resistor in the circuit. To find out how much resistance you need to add, subtract from the supplied voltage (by the power source) the voltage rating of the lamp and then divide by the current (ampere) rating of the lamp:
Resistance needed (ohms) = (supplied voltage – voltage rating of the lamp) divided by current (ampere) rating of lamp (in amps, not milliamps).
As for the street lamps, there are different types of street lamps available in multiple scales from various online suppliers.I bought mine from a Chinese supplier at Ebay, 10 pieces cost around Php 460 ($10), delivery is free via Chinapost and once it reached PhilPost, you need to pay Php 110 as handling fee.
To install the lamp, drill a hole smaller than the base of the lamp and thread the wires to the bottom of the layout. Then use silicone glue to seal the base of the lamp to the layout surface. The lamps should be placed out evenly along the street, 2 per city block on the average. Thread the wires to the bottom. Then extend the wires to a power unit. You could also wire these in parallel with other similar lights using power distribution block and have these all controlled by one switch.
Lighting effects are an excellent way to enhance the looks of your model train layout.