Writing starts with "I want"

So, it's NaNoWriMo, and though I'm not taking part, I am just starting a rough draft of book ten and thought it might be cool to detail out what I do as some of you are scrambling for page count.  Mine is zero right now.  I'm way behind.  I just finished the last of my personal rewrites on book nine.  (insert wild happy author dance here) and am ready to rip into the next, so what do I do first?  (disclaimer:everyone writes differently.  I've been developing my writing style for over a...