Your OKW guests need to be signed up with ME before the trip. I'm assuming you've already taken care of that.
When the plane lands at Orlando, they simply go to the ME registration desk. There will be a map in their ME registration packet along with their ME luggage tags. The luggage tags are put on their bags before they check in at their home airport. The next time they see their checked bags will be in the room at OKW. That's right, no need to go to baggage claim at Orlando - just head directly to the ME counter.
At the ME counter, they will verify the basics - what resort they are going to, how many checked bags and any arrangements for the return trip. Then they will be directed to the appropriate line to get on the bus for their resort. At the bus, any carry-on luggage they have (anything larger than a shoulder bag) should be given to the driver who will put it under the bus. Once the bus has loaded, it will head for WDW. Once at WDW, the bus may stop at other resorts before getting to OKW. The bus driver will announce the resort when stopping. They just get off the bus, claim any carry-on bags that the driver stored under the bus (a tip of $1-2 per bag is customary) and head for check-in.
Once checked in, they can either walk to their OKW unit, or get a ride from Bell Services. Their checked bags will arrive later (probably several hours later) so they should have a change of clothes and any needed med's in their carry on bags. The checked bags are supposed to be delivered to the room "magically", even if they are out. If its been longer than 4 hours since they landed, they might want to call bell services to see what the delay is.
You might want to read the "stickies" at the top of the Transportation board here on the DIS for more good info.
