Planning ahead means considering what could go wrong, and thinking of how you as the skipper will handle it--or how you crew will handle it if something happens to you!
Prudent skippers not only have a plan that they stick to, they also make sure the crew knows the plan, and can act accordingly in case of an emergency. When your guests come aboard, it's time to share information with them about your boat, and about your trip.
The information you need to share in this orientation will depend on your boat and how complicated things are. Try to establish a list of what can help your crew become better oriented to your boat.
Finally, make sure that someone ashore knows where you are going, and when to expect you back. Here is a simple float plan, provided to help you determine what information is helpful to rescue personnel. Leave your float plan with a responsible relative or friend - don't file your float plan with the Coast Guard!