Keith_Beef
Novice equestrian, accomplished equichetrian
Anything goes - be as wild as you want.
I think the other posters have put together a good list, but I've got a couple of ideas
I've been to a few yards that have a clubhouse/bar/restaurant. Often it is upstairs with very big windows looking down into the indoor school. When not being used as a bar/restaurant, these make good teaching areas.
On long rides, we stop off at yards so the horses spend the night either in a stable or a field. It would be nice to have a place to pitch a tent or even have some very basic accommodation for us riders at the yard, too. Sometimes we get lucky and our accommodation is within five minutes' walk of the yard, but sometimes it's a ten minute car drive away. On-site accommodation would also be useful if you want instructors to come to do classes over two or more days.