I doubt you will find many shelters that would turn you down as a volunteer. If you were able to give a lot of time you would probably see anything and everything you could imagine. I have no vet or vet tech experience but after working at our shelter I might as well be one! I have had to learn to deal with trauma emergencies, how to medicate oral and injectibles, and I assist with spay/neuter surgeries as well as a few other emergency surgeries. I have learned way more than I wanted to know!

As far as live births I would find a movie to watch. I'm sure there are some educational films out there somewhere. You commented about your pets getting pregnant but I'm hoping that they are all spayed or neutered.