Via Adam Wilt is a free (for now) PDF version of Droidmaker: George Lucas and the Digital Revolution, a history of early computer graphics and nonlinear editing. Droidmaker author Michael Rubin's presentations around the Bay Area upon the book's release were entertaining, and the book got the nod from Alvy Ray Smith, who with Ed Catmull co-founded Pixar.
Rubin has more on the same line, including early home movies of ILM from former ILMer and SFSU/MSP AE instructor Dave Berry (catch his life-affirming video Laugh if you can). Rubin also noted a web version of George Lucas: Maker of Films, a 1971 PBS piece with an interview of Lucas by film theorist Gene Youngblood, author of Expanded Cinema. There's additional background from source Binary Bonsai, who also noted the Raiders 125-page story conference transcript.
Youngblood's book itself is also available as a PDF download, if you're interested in expanded or synaesthetic cinema, an idea that includes visual music, experimental animation, and motion graphics. For more see the AEP post Visual music and motion graphics, which includes a 'making of' on Larry Cuba's computer graphics in the first Star Wars movie.