I went through the training about 2 years ago. It probably vaires from shelter to shelter. I recall the type and duration of the training depended on what you were going to be volunteering for.

I exercise the large dogs, help do obedience, pet education, and mini adoptions. I had to go be taught about the prodecure for taking the dogs out, sign them in and out, where the leashes and harnesses were. Also had to shadow the dog trainer to see how they were taught the commands, etc... Also had to learn more about promoting spay and neuter, how to detect cruelty to animals, teach kids how to be nice to animals. I also had to be taught how to do the screening and adoption paper process.

They also made me watch a movie on euthanasia. I bawled for hours.

Again, your training may be different. Good luck! I applaude your efforts in getting involved!