Two I can recommend to start with would be my book "In the Gravest Extreme: the Role of the Firearm in Personal Protection," and "In Self-Defense" by Mike Izumi, both available from Police Bookshelf, 800-624 9049.
I would also recommend taking one or more weekdays off and spending them in a legal library. You'll generally find one in the courthouse at the county seat of the county where you live. Yes, they're open to the public, and the legal librarians are generally delighted to see an ordinary citizen come in to take advantage of their facility. (Leave your gun in the car...it's usually part of the courthouse.)
Ask the librarian to show you where to find the statutes and criminal codes/penal codes of your state as they relate to weapons, self-defense, assault, and every type of homicide. Be sure to check the updated softbound supplements, which are generally to the right of the array on the bookshelves. Then ask to see the CJS, the Corpus Juris Secundum, and look up the same principles. This in turn will lead you to relevant caselaw. Finally, if they have a copy of "Warren on Homicide," plan on spending a few hours with that too.
That should give you a good start.
best of luck,