And maybe you already have your characters and themes set out, your world built, and your working title in place. You've laid in extra stock of coffee, and downloaded Scrivener. In which case, good luck, and I'll see you on the other side. But if you haven't gotten to that point, I have something else for you to consider.
Apply to Clarion. And take the month of November to write your application stories.
Clarion's application period is opening one month earlier this year, on 1 December. To apply, you need a portfolio containing two short stories, both between 2500-6000 words. It's not quite the endurance test of NaNoWriMo, but writing two complete, polished, short stories in a month is still a challenge. And if you need an endurance test, please believe that the six weeks at Clarion will take care of that for you. Sure, if you sign up for NaNoWriMo, you will get writing advice from brilliant, award-winning authors. Well, take a look at the Clarion faculty. Then think about the fact that not only will they participate in the round-table critique of your work, but you will meet with them for personal conferences.
I can't think of a fun acronym for "I wrote two short stories and applied to a premiere writers' workshop month," and yes, you could certainly do both, in that the application period for Clarion is open until 1 March, 2010. But consider the alternative to writing a novel in November.