Sadly I don't own anything bigger than a dinghy
and my only guests tend to be kiddies with anxiety issues
So in case you find yourself in a similar situation, with a somewhat reluctant or anxious passenger, here is what I do
1. show them the boat. Very brief run down of what the parts do and some basic nomenclature so they know what you're talking about if you say "sheet" or "tiller"
2. Have them put on proper fitting PFDs
3. Sail away from shore a little, then tell them that you're going to make the boat feel like it will tip over a little but that you'll then show them how to bring it back to flatten out, so that when they have a go they will know what to do in case it gets too scary (deliberate lack of jargon, both for adults and kids alike!)
4. Come up on the wind. Ease the main sheet and let the sail flap.
5. Repeat and get them to ease the main sheet until the boat is level again.
6. Go on a reach. Ask them if they know to make the boat stop. Usually someone will connect this activity with the previous one and will say something along the lines of ease the sheet
7. Ease the sheet
8. Tell them that if anyone falls overboard that that is to be their first action.
Most important of all is to at all times during the sail, STAY CALM. It's really tempting to overstress safety stuff but if anyone has a tendancy to become anxious, any emotion in your voice will be construed as anxiety and they will believe they have cause for panic. If your newbie looks uncomfortable, ask them what's wrong and make them comfortable.
Sailing with first timers isn't a time for egos, unless of course you're testing out potential team members for races, in which case - force 4 minimum, plenty of playing with the spinnaker and keep the leeward rail nice and wet