[sweetlee]

Call around and see if anyone has herding classes? Or go to some trials in your area and watch the dogs, and speak to the handlers.
You have the perfect opportunity with a flock of sheep available to you.
Lots of places charge big bucks to let the dog herd for a half hour.
If nothing else, take your dog to the fence on leash near the sheep and watch her reaction, make sure there is no aggression towards the animals, and then maybe walk her amongst them on leash and see what she does or tries to do. If you aren't wanting to compete, maybe you could just let her "herd" for her own pleasure and excersise. I have seen a couple of shows where people who have sheep charge city people to bring their dogs out and let them herd.
Maybe this would be a way to start? The herd owners do know enough to "read" the dogs reactions and certainly would not let an aggressive dog near their herds.
If your dog is already able to pass an advanced obedience class, most trainers go onto flyball, rally obedience, or agility. Start calling trainers and tell them your situation, ask if you can go and watch a class. Work with what your dog likes to do. For instance, my dog LOVES balls. This spring I am going to look into new classes for him, and one I will definately take a look at is flyball.

Sharon