Primarily, I'm interested in learning about other's experiences training their own dog to be an actual service dog. It would also be interesting to read about anyone who trained their own dog to be a therapy dog.
I'd also recommend checking out the Service and Therapy Dog forum on Dogster.com. Thank you for making a distinction between service dogs and therapy dogs!
By most definitions a service dog must provide you a service necessary for everyday function. For example, a medical alert dog that is trained to alert you if your blood sugar is too low or if you're about to have a seizure. Generally you do not train your own dog for this. Therapy dogs, however, are often trained from family pets and can be certified much easier as long as they behave well in social situations. Therapy dogs provide comfort to those around them and therefore are allowed in hospitals, nursing homes, schools (in some special situations), etc. Neither type of certification should be taken lightly- many people use false companies to certify their animals just so they can accompany them everywhere. This has made it harder for people with actual service animals to be taken seriously in their everyday lives, especially if that service animal isn't providing an obvious service (like medical alert).
Yes, I'm aware of this. That didn't answer the question. There are several reasons why an individual may train their own dog, who has already provided service tasks, before future help is needed, while the dog can still be trained, and before the person is willing to be medically certified.
Some hospitals will give you the information you need to get your dog's requirements in order to volunteer your time and have your dog walk around and visit the patients rooms.
Keep in mind that all trainings requires time and perseverance. Also all dogs learn differently and have strengths and limitations.
This answer really pertains to therapy, not service dogs....and the most basic understanding of training.