Doh - make that
www.ushga.org. Sorry!
Also, I was going to get you a list of schools, but it appears that the site is down right now: every state simply returns 'no schools' - I've reported the problem to USHGA and hopefully it will be fixed soon.
Originally:
You can take classes from a USHGA rated instructor, or a regular pilot. If you see the USHGA certification is current, at least you know the guy or gal has done some work in the sport recently. Otherwise, if you know the person and trust your life to them, then they're an option...
Yeah, sometimes... don't worry about it for the first 10-20 lessons though, you'll be using your instructor's equipment for training. It's not really renting, since they'll be with you the whole time.
Yes, there ARE. But as I said, you won't have to worry about that until you're at least a hang I, maybe even a hang II depending on how nice your instructor is. Also depending on their glider stock!