I've always been a hunter (mostly duck, dove and quail), not a shooter. But I shot a hell of a lot skeet to practice. In Texas it was cheap. You could go to a public range and have someone follow you around triggering targets for $10-$12 a round of 25, plus ammo. Given that you were using #8s or #9s it was cheap if you bought shells by the case. Sporting clays was more, about $30 plus ammo. Here in Fl? It freaking insane! I'd have to pay $500 a year at the range for the priviliege of showing up, and the $15 a round. Survey says no, and hell no. I'll look for a cheaper option.

Basically the shotgun games are these:
Trap. Here, you shoot at a target going up and away. Just one bird is in the air at a time. They don't present until you call for them. It simulates quail. Perfect scores are not uncommon if you're better at it than me and pursue it as a sport, not practice. Frankly, I think its a bit boring, but millions disagree and I'd always shoot several rounds before quail season.
Skeet. This is the one with the tall rectancular buildings. Its designed to simulate driven birds or doves or ducks. You call pull, and two clays are presented. Some high, some low. Its a two shot game. Again, if you're good, you can pop all 25. If you're me, you'll break less, but its still a lot of fun.
Sporting clays. This is my favorite, but its pricey. Basically, the idea is to simulate a mixed bag hunt. You walk along a trail and are confronted with different targets. It might be a high incomer like a duck. A chest level flyer like a grouse, or one 1 foot off the ground like a rabbit. Its up to the course designer to figure out what you'll see. Still, at 2-3 times the price of a round of skeet, I figured that my practice dollars would go further on the skeet range. If you're in it for the game, not to practice for bird season though, its a blast.
FQ13
If you can find a reasonably priced range go for it. Buy a 28" improved cylinder barell for that mossy, a couple of cases of WWB #8s, a PAST shoulder pad and have fun. Just rember to tip the guy pulling your targets.

FQ13