Don't spend today mapping out your plot, like you would if you had any sense. Instead, do what I do. Spend it sleeping (because you won't be doing much of that the next thirty days). Eating (like a chipmunk preparing to hibernate. Do chipmunks hibernate?) Buying an extra can or six of coffee, and possibly an extra coffee pot, to hold up to the demands of November. Walking your dogs, who are soon to be neglected. Make sure your laptop's plugged in to charge. If you're one of those crazy people who can write by hand, buy pens.
But don't spend too much time today stressing over your plot and whether it's going to make sense. Leave that for, oh, say, November 25-ish.
So have you signed up for NaNoWriMo yet? Who's with me?