I think your right to show them how to brew it, as opposed to simply giving them already made tea. I like to drink with others, if it's their first time. Ive turned 5 people on to the brew so far, always drinking with them. For whatever reason I think I can help / protect them better if I'm also in that state, because I truly believe that shamanism is real. I think the most important advise you can give them is to not fight it. I've also realized that there's no use trying to explain what the brew does, now I simply tell people that it is what it is, since people always ask me to compare it to some other thing, but it's not like anything else.
Resently, I drank with a freind, it was his first time. He was fairly anxious before we drank. When the effects began he said he felt a re-ensuring calmness come over him. We ended up drinking 3 cups each. Ultimately, there was nothing to be afraid of, although it can be scary and intense coming up the first time.
I would do it at home the first time, unless you have a spot in nature that's safe and extremely isolated with no chance of encountering other humans.