A must read

The Negative Trait Thesaurus: A Writer's Guide to Character Flaws - Angela Ackerman, Becca Puglisi

Dude, I'm already browsing through this book and I can think of so many authors who need to read this.  It's a great guide to character construction and making palpable conflicts and flaws - from flawed heroes to solid antagonists.  I have a feeling I'm going to be referring back to this quite a bit.