Hmm, videos ahead of time really are a good starting point. I do think though that the much maligned 'trial runs' suffer from a hidden problem. It's this : if you are nervous, or even worse scared, you can't learn, the higher brain cuts out and your basic, reptilian brain takes over. This one keeps you alive and runs the fight or flight approach to life, neither of which is great for boat handling, or absorbing what you are being shown. Tricky.
We always help newbies, but treat the 'they didn't tell us' comments with circumspection, in that they may have been told but couldn't receive. Thankfully, after a few days the penny drops with most people.