How do you install lighting in a doll house? Step by Step?

Question

Im new to miniatures.

Answer 1

See your other question for the when.

Like with full scale electric wiring you work with the power switched of.
Plan where you want lights, and if you want sockets, to use with plugs, or permanent lights that come on with a switch.
You can have an one switch only system, or make switches in each room, or even for each lamp, but that is a lot of work. If you want to be able to switch the lamps one at a time sockets and plugs might be best.
If you do not mind to see the wiring, it might be easier to repair mistakes if you do not hide the wires, but otherwise make sure all systems work before you wallpaper and so on.

For a beginner like you say you are it might be better to buy a set with batteries or a converter and an amount of wire and instructions, otherwise ask a lot at the shop.

The wiring is the same as full size wiring in a house, but as you work with low voltage-low wattage power, you can risk doing it yourself.
Books (or sites) on do it yourself electric systems might help you further.