I know Apple used to have a walk through guide for providing content to iTunes.
Every distributor is different though, so you might want to reach out to the distributor you think is at the top of your list to sell to and just ask them for their deliverables list.
Here's Netflix QC guide
https://partnerhelp.netflixstudios.com/hc/en-us/articles/115000353211-In...
I know Apple used to have a walk through guide for providing content to iTunes.
Every distributor is different though, so you might want to reach out to the distributor you think is at the top of your list to sell to and just ask them for their deliverables list.
As for Online, YouTube is a pretty good resource.
Hope that helps a bit. Best of luck!
Thank you, David!