You need to have a 'reservation' for DME. Be sure you book it through whomever you booked your stay with. Then, you will get in info packet about 4-5 weeks before you depart. In this you will find directions to the DME checkin counter, and yellow luggage tags for your checked bags, for each person on the reservation.
Put those yellow tags on any bags that are going to be checked. Get on the plane, have a great flight. When you arrive at MCO, head to Side B, level 1 of MCO. It's very plainly marked, and you will have your info packet (with map) in hand...do not pack it in your checked bags!!!!
You will get to the DME counter, they will ask you how many bags you checked, what your return flight is (times, numbers). Then, you'll be directed to the appropriate resort bus line.
Go to the line, when the bus comes you'll be directed to the proper bus.
You will then head out to the resorts. Each bus has up to 3, sometimes 4, resorts to stop at.
My average time, from deplaning to resort checkin, has been about 70 mins. I have been the first resort stopped at, the second, the third, and one time, the last.
The shortest time was abouty 55 min...going to POP, which was the first stop.
Longest was again, to POP, but we were the third and last stop, and there was a ton of luggage that guests had brought to the bus with them so it had to be stowed and then unstowed at each of the first two stops...adding a bit of time.
Now....your DME info packet will tell you to expect your checked luggage in your resort room up to 3 hrs after resort checkin. Most of the time, this is the case, but sometimes the wait can be longer. So....pack anything you may need for the first 6 hrs of your vacation in your carryon. It shouldn't be much...maybe a change of clothes, a swimsuit. But, you'll be able to start your WDW vacation without hanging in your room, waiting for luggage.
Any other questions, just ask. I'm sure I've missed something.