Set the time for people to show up at the departure site at least 15 minutes before you actually intend to leave. As a courtesy to your travelers, you should consider returning before 9pm on a night before classes. Be sure you include these times on the sign-up sheet and stick to them. Be sure to consider the facilities available and what size group will make for the best quality experience. Twenty people on a hiking trail at once seems like a freeway at rush-hour.
Animals flee before the oncoming hordes.
We suggest you limit your group size to 10-15. For overnight trips If you will be taking more than five people or be pitching more than two tents you will want to call ahead and see if you can reserve a group site. Food Marriott is an option. They can provide both box lunches and the raw materials for a meal. What they give you will be based upon how many paying eaters will be going on the trip.