Although it's unsexy compared to some kind of high-speed, low-drag shooting class, if you carry a firearm every day, you need to get yourself in a class regarding firearms laws and the law of self-defense in your jurisdiction. I know I consider the one I took to have been a very good investment of eight hours.
Hognose at Weaponsman.com just took one of Andrew Branca's (author of The Law of Self Defense) classes and wrote an excellent, detailed review of said class which you should go read in its entirety right now.
It has been my experience that the average state-mandated class (in states that mandate them) will do about as much for your legal knowledge as it does for your marksmanship, which is to say "nothing at all". Get you some good training; it could prove invaluable someday.