I have an 11-month-old filly whom I've had since the day she was born. She has manners on the ground, is starting to get the hang of lunging in both directions, and can ground drive/is in the process of learning to pull a cart. The other day I was watching her play in the pasture, and saw her do about three sliding stops all on her own. I think it would be fun to try our hand at reining when she's old enough. I've never trained a horse for a specific discipline, does anyone have any suggestions of exercises we could start doing now that will help her when she's ready, or can anyone point me in the direction of some good reading/a good trainer to look at?