There are going to be many times when your guests arrive earlier than check-in or are not planning on leaving the area until long after their checkout time. Instead of making your guests carry their luggage around with them all day, you should set aside a space to store their luggage until they need it.
Once you have this space, you can use one side for those who have arrived earlier than their check-in time and the other side for those who have checked out and are waiting until later to leave. You will want to make sure that their luggage is labeled well, and that you check every bag that a person removes to ensure that they are taking the right one.
It is a good idea to let your guests know that you provide this service and the easiest way to do that is to share it when you reply to confirm their reservation. You may also want to remind your guests of this upon their check-in, so that they know the option is there on their departure day.