If you are flying out of Orlando on a flight operated by American, Continental, Delta, Song, JetBlue, United, or Ted, check your luggage with Resort Airline Check-in at your resort. It's great! You'll even get your boarding passes. You can use Resort Airline Check-in in the morning, even if you're not flying until the evening. You don't have to touch your luggage again until you get to your home airport.
If you're not flying on a Resort Airline Check-in airline, just leave your bags with the bell service desk (for the equivalent) at your resort. (I don't know POP has bellmen who will come to your room, but I understand you can check luggage at the lobby.) They'll store your bags for you and give you a claim check. You'll need to retrieve your luggage before your scheduled DME pickup time. (It's customary to tip when you retrieve your luggage.) Your DME driver will load your luggage into the luggage hold of the DME coach, and will unload it for you at the airport. (It's customary to tip when the luggage is returned to you.) Then, just check with the airline (or with a skycap, in which case it's customary to tip) as you would if you had arrived by taxi or towncar.
