Stephen King: Uncollected, Unpublished - Hard Cover 4th edition

Major Updates in this Revised and Expanded Edition of Stephen King: Uncollected, Unpublished are only found in this edition. There are a multitude of interesting updates in the revised edition of the classic book about King's hidden work. This edition is likely to prove to the definitive book about King's uncollected, unpublished and lost works. Included in the new information are a series of newly discovered unpublished works - for many of these the author was able to secure Stephen King's exclusive and definitive statements about how they originated, and why they never saw the light of day. Many of these quotes are entertaining and even controversial. Previously unknown works include: Hatchet Head; The Ladies Room; another incomplete Western novel, and many more newly discovered works of Stephen King fiction.

Review from Fearnet.com:

For a writer like Stephen King, who has put out work in a nearly non-stop frenzy since the 1960s, it is almost unthinkable that there's work he hasn't published. With over fifty books, scores of short stories, and a bafflement of non-fiction pieces, King is one of the most prolific writers of our time ... or, really, any time. What may surprise the uninitiated is that beyond the shiny bestsellers, there's a whole wealth of underground Stephen King material: work that has been published but never collected, work that has never been published, and work that has never been finished.

Wood covered (and continues to cover) it all - unpublished novels, unproduced screenplays, juvenilia, uncollected and unpublished short stories and poems, and non-fiction pieces. 
This update, the book's fourth, is the most significant ... (it) benefits from direct contact and comments from Stephen King himself.

King's involvement helps the book in two ways, the first and most obvious being that it clears up a lot of misconceptions about the validity of King's work. Over the years, a number of assumptions have been made about King's unpublished writing, sometimes wrong and sometimes misleading; as time goes on, some of those assumptions have become, for all intents and purposes, facts. Wood has waded through the apocrypha and gotten the gospel from the only man who knows the truth.  But while it's terrific to get the facts straight on King's unseen work, what really makes this version of Uncollected, Unpublished come alive are the quotes from King, reminiscences that cast a human light on this deep history of dates and titles and plot synopses.