Free preliminary training is always a good place to start. Reading textbooks, investigating unbiased Internet websites and talking to qualified electricians will give you a good feel for what's involved.
Bear in mind: This is just preliminary training. You cannot substitute classroom education with free resources. Finer points, such as how to correctly wire in a breaker panel, cannot be obtained by just reading a book.
Many community colleges offer classes in house wiring. These classes can be taken for credit or for personal knowledge (non-credit). You will learn correct wire placement, correct terminations to outlets and switches, and code adherence.
Trade schools also offer training in residential wiring similar to that received at community colleges. You will learn correct wire installation, how to correctly wire in outlets and how to correctly install conduit from the service entrance to the breaker panel.
Hundreds of trade schools offer residential electric training. Investigate what schools near you offer residential wiring classes. For example, the Berk Trade and Business School in Long Island City, New York, offers a program in electrical installation.
Some electrical contractors will hire a person with no skills and train him step by step. This usually happens during construction "boom" times, when electricians are in short supply. When hired on, you will be given the physically demanding jobs, such as carrying wire spools or lugging tools -- in essence, all the hard labor "grunt" jobs that require little or no skill. As time passes, you will learn advanced wiring techniques, and complete tasks according to your skill level. Experienced electricians will obtain a license and may go into business for themselves.