Most of my shooting experience has to do with real bullets (.22 and .45 caliber) punching holes through paper. It probably doesn't matter so much with paintball guns, but with a real gun, the key to accuracy is being smooth on the trigger. When you're trying to line up a shot at 50 yards, being smooth is sometimes the difference between a 10 (inside a 3 inch diameter circle) and a miss (outside a 3 ft diameter circle).
In paintball, it's probably more important that you correctly judge the projectile's arc.
If you're shooting iron sights, line up the front sight so that it's directly in the middle of the notch of the rear sight and the the tops of the front and rear sights are level. In other words, line up the front and rear sights both vertically and horizontally. Once you have that down, line up the top of the sight with the bottom* of the black circle on the target. This is called a 6 o'clock hold. However, DO NOT focus on the target. Instead, focus on the FRONT sight. Do the best you can to hold it there (the gun WILL wobble, there's nothing you can do about it) and smoothly squeeze the trigger straight to the rear with only the trigger finger until it goes off. Do everything right and you will be rewarded with a fairly accurate shot. If you're serious about becoming a good shooter, start with .22 for at least a few months before moving up to the larger calibers.
*The other option is called a center hold. As the name suggests, this involves aiming at the center of the black, rather than the bottom. On guns with adjustable sights, the shooter can decide whether he or she wants a center or 6 o'clock hold and adjust the sights accordingly. If the sights are fixed (non-adjustable), then chances are you'll just have to figure out where the shots hit, in which case the 6 o'clock hold is merely a starting point.
One of the more popular types of sights in competative pistol shooting is an electronic red dot sight. On the one I use, there is a tube on the top of the pistol, a little bit like a rifle scope (although shorter). Rather than crosshairs, there is a little red dot in the center of the sight. In this way, it's a little bit like a laser sight except that no image is projected on the target. There main advantages of this sight include: no need to line up the front and rear sights and easy sight and target acquisition. It is also (almost?) universally configured for a center hold and is therefore more intuitive to use than iron sights. Just put the dot in the center of the target and squeeze.
In paintball, it's probably more important that you correctly judge the projectile's arc.
If you're shooting iron sights, line up the front sight so that it's directly in the middle of the notch of the rear sight and the the tops of the front and rear sights are level. In other words, line up the front and rear sights both vertically and horizontally. Once you have that down, line up the top of the sight with the bottom* of the black circle on the target. This is called a 6 o'clock hold. However, DO NOT focus on the target. Instead, focus on the FRONT sight. Do the best you can to hold it there (the gun WILL wobble, there's nothing you can do about it) and smoothly squeeze the trigger straight to the rear with only the trigger finger until it goes off. Do everything right and you will be rewarded with a fairly accurate shot. If you're serious about becoming a good shooter, start with .22 for at least a few months before moving up to the larger calibers.
*The other option is called a center hold. As the name suggests, this involves aiming at the center of the black, rather than the bottom. On guns with adjustable sights, the shooter can decide whether he or she wants a center or 6 o'clock hold and adjust the sights accordingly. If the sights are fixed (non-adjustable), then chances are you'll just have to figure out where the shots hit, in which case the 6 o'clock hold is merely a starting point.
One of the more popular types of sights in competative pistol shooting is an electronic red dot sight. On the one I use, there is a tube on the top of the pistol, a little bit like a rifle scope (although shorter). Rather than crosshairs, there is a little red dot in the center of the sight. In this way, it's a little bit like a laser sight except that no image is projected on the target. There main advantages of this sight include: no need to line up the front and rear sights and easy sight and target acquisition. It is also (almost?) universally configured for a center hold and is therefore more intuitive to use than iron sights. Just put the dot in the center of the target and squeeze.