Head to the "See Disney World in 3D" link at disney.go.com (see Resource links for a direct connection), and view the video of Professor Ludwig von Drake. He's a very helpful duck.
Download Google Earth on your computer, if you don't already have it. You can do the download at the Disney World site or directly from Google Earth (see Resources for links).
Once in Google Earth, simply search on "Disney World", and then click on the Mouse Ears (what else!) to begin your virtual tour.
Enjoy your tour! How often do you get to tour Disney World absolutely free?