You seem to have covered most of what you need to get started, and pretty impressed with the organisation tbh... but one thing I will say is that private lessons are all very well and good, and you probably get more individual time and help, I would always suggest group lessons for beginners.
As an assistant instructor myself, the thing about group lessons is that there is a feeling of camaraderie (especially teaching adults). You get to compare your progression with people around you to a degree, and you can see what other people are doing and see the different styles of riding. Hearing what other people are doing wrong helps keep you in check too! Plus, when you're new to the sport, and half hour (or longer) private lesson is very intense, and muscles not used to it can complain a lot. It's also a long time to concentrate without a break, which riding with others gives you as you each take turns, but you're still getting the horse time that helps you develop your position etc. Just something to consider. But I'd agree with the adult lessons - people over about 16 tend to progress very differently from those who are younger, quicker in some areas but slower in others, so I;d recommend adult group lessons if you can.
I'm UK too, and btw, 18 quid is a very decent rate I'd say. You're usually looking 20-25 quid for an hour group of half hour private, certainly in horsier areas or more touristy ones, and that's without investing in a helmet (£30+ for a semi-decent one, but most good ones look in around £50-100), jodhpurs (you can get cheap, low quality ones online for £10, but tack shops you're looking probably £20+) and boots (from £30-40 for cheaper, rubber type long boots or jodhpur boots, and much more for leather long boots...). It's an expensive game, I'm afraid. I tend to put it on a par with skiing - probably the same kind of risk level, as in more than most sports but not too bad if you're sensible of your skill level and have a good instructor, and both aren't exactly cheap sports... However, all you need to get started is a pair of walking-type boots, a pair of jeans and a warm jumper, most riding schools have hats you can use for the first few session while you try it out.
I hope you enjoy it, it's a great sport and whilst it can be tough to begin with, especially as an older person learning to ride (even by late teens people are never quite as fearless as the kids are!), it's the most amazing feeling when you get it right. And whilst you say you don't want to compete, and I'd agree that's a good attitude to have for now, don't rule it out - if you catch the bug, you may be desperate to by this time next year! Especially if you are a sporty person already, we tend to have a bit of a competitive streak... and there's nothing like the exhilaration of a cross country course for example.
Good luck, and enjoy yourself! Don't worry about the parents, you may be surprised by the reaction and if not, let them them see what the sport is really about, and how tough and athletics you have to be!
Last edited by minstrel; 04-24-2012 at 06:46 PM.