GSSF

Before you go off to the shooting match, you're going to need a few things. The most important thing to bring to a shooting match is a gun. Glock, inc is no less stringent on this matter than most competing organizations. You definitely need a gun. Additionally, Glock requires that that gun be (surprise, surprise) a Glock . Glock's purpose in putting on these matches is to promote their favorite pistol. Glock makes little or nothing on these events directly as it spends the money it takes in on prizes and administration of the event. As a result, they wrinkle their noses if you show up with, say a Smith and Wesson Sigma. The up side of this is that you get a pretty even playing field. That 12 year old to the right of you who just smoked six steel plates in under four seconds is shooting the same gun you just used to barely get all of them down in half a minute. This is a competition of shooters, not gunsmiths or bank accounts. Hard on the ego sometimes, but you don't have to wonder much about why you scored where you did.
Next, you'll need a few magazines. There's no need to go out and scrounge up some high caps at a hundred bucks apiece, it won't matter. The course rules prohibit loading more than 10 rounds in a magazine, so the standard 10 rounders will do nicely. You could get by with one magazine if you needed to, but this would slow things down a bit as you'd have to stop and reload between runs on every stage (Glock.com covers stages and runs in more detail) Four is good, that's the most you'll have to shoot without a pretty good break.
Third, you need something to carry it in. The box it came in will do nicely. You can also use a holster that permits the gun to be carried with the slide back. A shooting bag will work nicely also.
Fourth, you need hearing protection and eye protection, both available at Wal-Mart and elsewhere and are fairly inexpensive, and last but not least you need some ammo. Two boxes will get you through if you shoot one category (you can shoot in a few usually, but one is a good start, more on that later)
That's it, no dot scope, no personal trainer, just a gun, some ammo and a box.

For starters, you should probably practice some. How you practice may be as important as how much. The trick is to practice as closely as you can what you're going to be shooting on match day. The GSSF matches are broken down into three stages, called Glock Plates, Glock M and Five to Glock. Your total score is the total amount of time, in seconds, you took to hit all the targets plus lotsa "penalty seconds" you get for not hitting the targets in exactly the right place. For example, when you shoot the "Tombstone" targets on Glock M and 5 to Glock, if you hit the "10 ring" you don't get any seconds added on. If however, you happen to stray into some obscure corner of the target, they add five seconds to your time. Five seconds is alot of time, so it pays on these stages to take your time and aim at the center of the target. This is not an easy thing to do with a clock running over your shoulder, shots firing all around and several dozen steely-eyed competitors glaring at you. In order to do this well it helps to have done it a few times before, in practice. You can get the particulars about the match at Glock.com, so I won't bore you with them here. I have found that practicing with reactive targets, bowling pins, tin cans, balloons, or whatever, yields much quicker results than shooting at paper. Don't get me wrong, paper has its place. You need paper to see where all those bullets that are missing the bowling pins are going so you can correct your sights, grip, or whatever else is consistently throwing you off. There is no better way to correct your mistakes than shooting reactive targets, though. They provide instant feedback. When you do it right the target falls over, you remember what you did, how it felt, and maybe you can do it again. Bowling pins are by far my favorite targets, aside from steel plates, which are pretty expensive. You can get a box of "bad pins" from your local bowling alley for free or nearly so. They last a long time, they don't make a mess and they're fairly easy to carry around. If you're stuck on an indoor range, blow up some balloons, tape them to the target and run them out there. Happy shooting.

First you have to find a match. They're scattered all over the country , and occur mostly in the summer. Glock.com will fill you in on the particulars. You have to join the GSSF club, which costs about $50 per year, and then you have to pay about $35 per class to shoot. It's a good thing to preregister with Glock, but you don't have to. GSSF has several classes for shooters. The one with the best odds of winning a gun is the amateur civilian class. You can shoot in another class if you want. This gives you a little more trigger time, and allows you to run through it once in a class in which you have no chance to win before you go for the big bucks. I usually shoot competition class and then amateur. There's a special class for subcompacts, the concealed carry Glock 26, and 27's and others for police officers and master class shooters.
When you arrive and pay your money they give you three pieces of paper. These are score sheets. You should put your name at the bottom and then take them out to the various stages so the range officers can put you in the pile. This can be done one of two ways. First, you can put your name in three piles of your choice and wait by the one you think will call you first, based on how far back you are, and how quickly things are going. If your name comes up on another list and you don't answer they just go to the next shooter, and then start at the beginning of the list again for the next round, so you don't go to the bottom of the list or anything. The second method is slightly more dynamic. It involves putting them in one at a time and using the intervening time to get an idea about which of the several set-ups for the same stage is moving along the fastest. At smaller shoots there may only be one or two set-up's running and this may not be of any help, but some shoots are quite involved and may have six or seven set-ups for the same stage, and some go more quickly than others.Both methods have their merits.
The next step is the toughest. From here you have to wait....and wait. Most matches take 3 hours and involve about two minutes of trigger time. That said it's a hell of a lot of fun and a great way to improve your shooting skills.
Shoot Fast...don't miss. Happy shooting.