I used to be a working student at a local eventing barn. Basically, I cleaned the barn, set up jumps, and taught the younger riders basic horsemanship. It was fun and honestly I would have done it for free. There is another barn in my area that has an even better working student and even an internship program. In it you do everything I just mentioned but can bring your horse to the barn and have one free lesson a month. They have an indoor exercising pool for the horses, large arenas, and a half mile track. It is a great deal, but I have a job and can't commit the hours every week to do it.