Answer:
This is a very basic and simplistic description of how to wind a transformer. The first thing that you have to establish is what is the primary voltage you are going to use and what voltage do you want to appear on the secondary side of the transformer. Find the ratio between the primary to secondary voltages. Wrap your flexible insulating material around your iron core. Wrap your magnet wire around the iron core to form the primary coil. Depending on what type of iron core that you are using (there are many different types) wrap your secondary coil to the ratio of turns that you have calculated to obtain the secondary voltage that you want. Sometimes the secondary is wrapped over the primary coil with insulation material between the windings. Never wrap the magnet wire directly on to the iron core, always use use flexible insulation material. The insulation on magnet wire is just varnish and if the wire is directly applied to the iron core, the 50 or 60Hz frequency vibration will eventually wear through the insulation and short the winding out.