Hi I know you posted this months ago but looks like you never got an answer...
Here are a coupld of links that should help you with information on how and where to get started.
http://www.deltasociety.org/AnimalsR...sEducation.htm
http://vachss.com/help_text/animal_training.html
Also, check with your local dog training groups or AKC All Breed Club as they usually offer courses for you and your dog such as CGC training (Canine Good Citizen) which prepare the dog for Animal assisted therapy work. :-)
Please let us all know if you get involved in this wonderful work with your dog!
Jeannie Thomason, V.N.D.