The National Electric Code is a document sponsored by the National Fire Protection Agency. It is a book electricians will have to learn before obtaining there license. Most electricians can find articles easily because they have spent so much time studying the book. For a person looking thru the book for the first time, it would be easier to use the index in the back of the book. The National Electric Code is a guideline for electricians, electrical contractors, engineers and inspectors.
Most states require a permit and inspection.
While going by the NEC will not guarantee safe electrical installations, it is the best guide available. Every state may differ slightly in their requirements for inspection and code compliance. In most areas the local wire inspector is The Authority Having Jurisdiction. The authority having jurisdiction for enforcing the code will have the responsibility for making interpretations of the rules. For more details on the N.E.C. try Mike Holts Web Site.