I have to say, I'd never appreciated Stephen King's wit quite enough. I read a few of his books, most notably, 'Salem's Lot, and I've seen a few of his movies (The Stand ranks among my favorites), and appreciated his ability to dig deep into the reader's primal fears and bring them dripping and squishing onto the page.
King offers a lot of the history of how he came to write in the book. As an autobiography it's humorous and interesting. The meat of the text is in his advice to authors, though. I'll use those chapters as a reference throughout my writing career.
If you write, if you want to write, if you're researching writing, read this book. You'll be inspired, education, entertained and enriched.