The is precious little written on the history of Walt Disney World (the few books I have on this topic were not all that informative), but there are some very good books on the history of
Disneyland. The best of these is "Disneyland, The Nickle Tour" by Bruce Gordon and David Mumford.
E-Ticket magazine has 2 CD's which contain most of their back issues. E-Ticket is the best mag on the Disney parks out there, with lots of inside stories from the imagineers and many historical articals on Disneyland. The CD's each contain approx 15 issues and are well worth your time. Heres a link for more info:
http://www.the-e-ticket.com/CDROM.html
For Disney World history, you might try reading Bobb Gurr's column (Designer Times) on laughingplace.com. He wrote 3 or 4 coumns there on his experiences building Disney World. For books, "Walt Disney World, A Magical Year by Year Journey" (out of print, but resold on
Amazon) and "Since the World Began" (available on Amazon) both give a good chronology of what was changed when in the parks and have lots of great pictures, but they don't have a lot of inside information on the design and building of WDW. "The Haunted Mansion: From the Magic Kingdom to the Movies" is a an excellent detailed reveiw of the work that went into all of the Haunted Mansions Disney has built around the world. Its an OUTSTANDING book for Disney park history fans. I have also heard good things about "Vinyl Leaves", but I have never had a chance to read it.
For imagineering in general, I highly reccomend "Designing Disney's Theme Parks: The Architecture of Reassurance" by Karal Ann Marling , "Walt Disney Imagineering: A Behind the Dreams Look at Making The Magic Real" by the Imagineers and "Designing Disney: Imagineering and the Art of the Show" by the late, great imagineer John Hench. All of these are excellent reads