Stand Your Ground laws are self-defense laws that give an individual the right to use deadly force if their life is in danger without being required to "retreat" from the situation even if possible.
The Castle Doctrine and "stand-your-ground" laws are affirmative defenses for individuals charged with criminal homicide. It states that one can use deadly force if necessary in order to prevent any crime the intruder would commit. It not only backs the owner but the people who are allowed onto the property as well to be able to stand and fight back.
This document gives a great insight into the Stand Your Ground Law and info on the States and when they adopted the law. Goes more in depth with certain asspects of the law.
Trayvon Martin is far from the only shooting in which the controversial law has been at issue. This webpage tells about 5 other stand your ground cases and links to each.
This webpage specifically states what Arizona's Stand Your Ground Law says. It is the direct link to the Law and the Arizona State Legislature webpage.
This webpage gives examples of which states have the Castle Doctrine. It explains the differences between the strong and soft Castle Doctrine by state.