I wrote Harry, Revised using plain old Microsoft Word, but I am writing my new novel using Scrivener and I am completely devoted to it. It's an incredibly flexible tool, and it's helping me arrange a book that I am not writing in a linear fashion (unlike Harry).
Why is this relevant to any of you? Because Lifehacker is reporting an extended trial of the beta versions of both Scrivener's new Windows product (until now it's only been available for the Mac) and the 2.0 version of the Mac product. The free period is set to coincide with NaNoWriMo and expires early December. The software is 45 bucks and it's life changing, so if you've been struggling with getting your manuscript organized (or under way), I strongly urge you to give Scrivener a whirl. (And no, this is not a paid endorsement!)