Our editor at Poisoned Pen Press, Barbara Peters, posted this article to the hibernating PPP blog and it is so useful I thought I'd mention it here.
Ten Mistakes Writers Don't See

appears at Holt Uncensored, a semi-monthly email column and website about books and the book industry written by Pat Holt, former Book Review Editor and Critic for The San Francisco Chronicle.

This isn't theory. It's an amazingly practical list of the exact things I always have to correct.