At the crossroads

I'm at a crossroads in my writing, and as always when I arrive here, I'm reading how-to-write-a-book books. My critique partner Cathy loves these books even more than I do. My critique partner Vicki never touches the stuff. How about you? What are some of your faves? For good or ill, has a writing book ever changed your direction at the crossroads? Come discuss at the MTV Books Blog.