I believe it was in August of 2001 (from when this title came), before my love of The Spirits Within was solid (I was, however, more interested than I had been in a FF since FF6), I came across this title at My Local Best Buy.  I instantly recognized the cover face of this hardcover book, though it hadn't been in my mind recently, and itwas soon with me on my way home, having mostly ignored the "Great graphics, but not that good a movie" remark by My Local Best Buy Cashier.

Published by BradyGames, and apparently edited by one Steven L. Kent, this Making of title is contains a plethora of information on much of the inner workings of The Spirits Within.  This is both story information and the piecing together of stage and players.

Among other things, and not in order, it has:

Character bios and stats, along with actor info.

Information on all the gadgets and props used in the film, also in story context.

A near-final draft of the script.

A foreward by Sakaguchi.

A moment on the Gray Project and Thriller minis.

Concept Art and Animation information.

Storyboards.

And Motion Capture information.
 

All I can say is, for anyone who wants to know more, this is your book.  Yes, there are better, but only if you read Japanese.