You need to know what you 'want' to do.
"Man needs to know his limitations"
Seriously.
If you want to just 'Do It' and get the best damn intro to carry there is, sign up for an LFI course up in New Hampshire. Lethal Force Institute run by Mas Ayoob is hands down the finest I've ever had for what it covers.
If a week of your time, $800 and a case of ammo is a little much, there are other alternatives.
GOAL's Art of Conceale Carry is a nice primer to be sure. For the time it has, I don't think you'll find more information for your hour or dollar.
I also like Lyn Bates class "Responsible Use of Lethal Force" and "Self-Protection with Handguns" taught by AWARE (
www.AWARE.org)
SIG's Defensive Handgun course is great for the shooting drills, but I found the legal bit a wee light.
I have not tried the Smith and Wesson classes yet, but hear that they also do a great pistol tactics offering.
I've done the Gunsite and Front Site classes as well, but frankly, with the exception of the wide open spaces, instruction here is as good or better than what I had there. (although the round counts at Gunsite were amazing)
I still have to make one of the PSI clases by John Peterson, but knowing the folks involved, I can tell you that the caliber of instruction is quite high.
The staff at Riverside are working on an defensive pistol course, and will continue to bring in guest instructors.
I can also reccomend reading Mas Ayoob's "The Truth About Self-Protection". Chapter One does a fine job of really describing what it is that you will be facing if the animal comes for you. The rest of the book is good quality information. However, no book is going to beat a live instructor.
Most importantly, go out and practice. Get to know your gun in various weather types. I'll never forget one of the first Action Pistol events we had (this was before we were IDPA) where it was cold, damp, and drizzling. Every single 1911 style pistol that day had feed problems. Glocks would not seat their magazines properly, and just about everyone had some kind of equipment issues.
Most clubs allow the following drill - if not, meet with the board and see if you can get permission to do it.
Drive a tent spike into the berm near the top. Tie some paracord (or other strong but light cord) to the spike and then to a large empty laundry bottle near the bottom of the berm.
Fill your gun. You want to get the bottle moving. If you shoot the bottle, it will sit there and start looking like swiss cheese. If you hit just below the bottle, the bottle will jump. In the beginning, focus on making each hit cause the bottle to jump. Later, as you get good, seek to keep the bottle moving until you run out of ammo.
I then took this and started informal 'Action Shoots' with cover and odd shooting positions.
Eventually that became IDPA. The idea is that the shooting becomes second nature. You point the gun and you hit your target. Man size targets at combat distances are not tough shots, but you need to get to the point that YOU are confident that you can make the shot on demand.
At this point, you can start adding the tactics, shoot/no-shoot decisions, etc.
Set goals and achieve them. Somethng simple like "This month, I will shoot the bottle and half my shots will send it flying." Simple achievable gols are best. Doesn't matter if you end up setting thee goals in one afternoon if you are on a roll. Expect that you will have 'off' days and forget the goal and just have fun.
Get involved with a competition. Even if it is some informal club thing between buddies. ONLY when you are pressed to exceed your ability will you do so.
If at any time you make the effort become 'work', stop and reevaluate. When it is no longer just fun, it might be a signal that you are either trying too hard, or perhaps you need someone to watch you to find what you are missing. I've seen top High Master shooters call over more novice friends to watch them shoot because even the most obvious of things can be completely invisible to yourself, but appear as if in a spotlight to an observer.
Hope that helps.
Chris