NaNoWriMo is during the month of November, through the entire month people far and wide challenge themselves to write I believe 50,000 words of a novel. It's quite the challenge but a rewarding experience, though the writing itself doesn't turn out very good.
I hope that answers your question.
If you have anymore questions you can PM anytime.
Kamas
"Nothing is permanent in this wicked world - not even our troubles." ~ Charles Chaplin