My sister just sent this to me a few weeks back. It's entitled EMPIRE BUILDING: The Remarkable Real Life Story of Star Wars. It was written by Gary Jenkins. Published by Citadel Press.
Anyway, it's a fascinating read on the behind the scenes of the OT. And even has an updated section about the making of TPM.
If you're at all interested in Film Making -- or what went on back stage, this book is great. There's also a few interesting on the set photos too. Kids as Jawas. Ponda Boba getting direction . . .
The book also details the end of the Kurtz/Lucas partnership. At one point Lucas went ballistic, even yelling at Kurtz, Kershner and the editor "You're ruining My Movie!" at the screening of the rough cut of ESB.
Definitely worth checking out.