Wikiversity resources for assistance dog training include chapters of a textbook Motivation and Emotion and WELP, a moniker for a research project and learning resource for owner-trainers. The latter may include a textbook, a curriculum, instructional videos and templates for training logs.
The following summary, creditable to Wikipedia as of September 1, 2020, is broadly accurate and will be refined on this (Wikiversity) project:
Once a puppy is old enough they will commence their specialist training which will include training in work and/or tasks. It is these tasks which will make them distinct and specialised assistance dogs. In the EU to be categorised as an assistance dog, a dog is expected to have at least three specialized tasks which mitigate the owners disability, while in the USA an assistance dog handler may be asked if they have a disability, and what tasks the dog does to mitigate that disability as the only 2 legal questions to ascertain that a dog is indeed an assistance dog. The tasks that an assistance dog prospect will learn depend on the disabilities that their current or future handler has and there is therefore almost no limit on the types of tasks a dog can be trained to. These may vary from pulling wheel chairs to interrupting self-harming behaviors to providing deep pressure therap. A resource on the internet, which has not been peer reviewed or audited by this Wikiversity project, has published something called "The Giant List of Service Dog Tasks", which seems to be at least an inspired concept which may be of use to some. 
- US Department of Justice. "Frequently Asked Questions About Service Animals and the ADA". Retrieved 25 August 2018.
- Froling, Joan. "Assistance Dog Tasks". IAADP. Retrieved 25 August 2018.
- "Gigantic List of the Top 150 Service Dog Tasks". The Atomic Hound. Retrieved 2020-09-01.