Come on Cass. You guys are always understating my credentials. Unlike many people on this Board I am fully unlicensed to plumb in each and every State, and that includes Puerto Rico and Hawaii too. In fact I can proudly say, and after a great deal of studying, I cannot legally do any remodeling work for anybody other than myself in any country.
In most areas homeowners are allowed to do electrical and plumbing work within their own residences, however the particulars vary from locale to locale. In some locations it can be as simple as obtaining a permit, while others may limit the scope of work that can be performed or even require aptitude testing before a permit can be issued.
Ultimately it is the sole responsibility of the homeowner to learn about and comply with all ordinances relating to DIY work and permits. Some good sources of information would include the local building department, electrical and plumbing inspectors, and, in some cases, the local power/water company's customer service department.
However, obtaining a permit does not automatically make someone qualified to do the work. The National Electrical Code, for example, defines a "qualified person" as one who has skills and knowledge related to the construction and operation of the electrical equipment and installations and has received safety training on the hazards involved. Jurisdictions are free to use this definition or any other and it is the responsibility of the person doing the work to learn and comply with any requirements in their local jurisdiction.
Using this Forum alone is not enough to make someone qualified to perform remodeling work, however it can be used by novices and beginners as a first step in gaining a better understanding of how household plumbing and electrical systems work. For those with more experience (like Cass), it is a great tool for furthering their knowledge but still is no substitute for real world training and experience. Performing DIY work around the house is a satisfying and rewarding experience but one should always be aware of their limitations and call in a professional licensed contractor if the scope of work exceeds their abilities, and then call in Cass when the forementioned professional licensed contractor messed up and didn't do it right the first time.