It's coming! Midnight next Friday, is the beginning of National Novel Writing Month: November 1 to November 30.
What is it? It's a month when people all over the world set aside time to churn out bad novels ;-)
The goal is to have at least 50,000 words by midnight November 30. Since you must write fast -- 1667 words per day -- there isn't time for editing or perfecting or even worrying over whether it's good or not. And that's the whole point! One of the biggest obstacles to writing is running commentary from our internal editors on how bad something sounds and how trite it is.
For NaNoWriMo you send your internal editor on vacation. It's not allowed to contact you at all. While the editor is away you let the ideas flow out of your fingers. There will be a lot of bad ideas! But mixed in will be some good ideas, even great ideas that would have been blocked by the critical voice of the editor.
The novel doesn't need to be complete. (Most commercial fiction is between 75,000 and 100,000 words.) It doesn't need to flow. You can leave scenes that aren't working incomplete to move onto another scene that's trying to get out.
No one will read it. You'll upload your final document to the automated counting bots at NaNoWriMo and they will count your words. If you have 50,000 words or more, you win! Win what? Win the satisfaction of being one of the elite who has completed a novel :-) And a nifty downloadable certificate that says you won.
My daughter Kat (now 17) and I have done it four times. And while insane, it's also a lot of fun and rewarding too. How long does it take? Basically it depends how long you give it! Most people are doing this while holding jobs or going to school and can only write in the evening or on weekends. Kat and I give it all day and have found it consumes whatever amount of time you give it. ;-)
While you can't begin writing until November 1, you can plan as much as you want. I've done it 4 times without a plan. An idea comes to me the week before or sometimes the day before and I just let it take me where it will. Some like to know where they're headed. Some like the adventure to unfold. Which is better depends on what you find works for you :-)
Most areas (even in other countries) have local groups that meet occasionally throughout the month for writing and moral support. They're listed in the Regional Lounges section of the forums at the NaNoWriMo website:
There's also lots of online support in the forums, tricks and tips, word challenges, even places to ask obscure questions (like, for example, whether someone could carry $1 million in $1 bills.)