
Author Michael Rubin has put his exhaustive history of the special effects empire George Lucas assembled together available for download free of charge on his personal weblog.
You can download it in three parts.
I've been going through the book and have marveled at the level of detail Rubin was able to get out of this story that's been going for a far longer time than I would have guessed.
In fact, it's so good, I'm seriously considering buying it. If you like what you see, you owe it to the author to pick it up on Amazon.
From what I've read, you won't regret it.