It's December. That means that those of you who were working on a novel for the National Novel Writing Month are in the clear by a significant margin. Heck, I had to postpone this article for a week just so that I could think clearly about the topic. Assuming you finished your rough draft (and if you did, good for you!), now comes the time to decide what to do next.
The main thing that you absolutely do not do if you value your reputation as a writer is send your rough out to publishers as-is. I've heard of this happening and it makes me throw up in my mouth a little bit every time. And even if you think its the finest contribution to modern literature since Pride and Prejudice and Zombies, for the love of your deity of choice do not self-publish it as-is. I've heard of this happening and my faith in humanity crumbles a bit more every time.
You take that rough draft and you put that sucker away for a while. I'm not even going to look at Necromancy Will Kill Your Dating Life until January. Stephen King recommends letting your draft hang out in solitude for six weeks. Why? Because when you do pick it up to look it over and unleash the fury of your red pen on it, you'll be able to do so with the level of detachment this process requires.
What to do in the meantime, though? Lots of things. Read. Work on another rough draft (I have a whole pile of works in progress I could pick up). Edit another manuscript. Do what you can to clear your NaNo novel from the front of your mind. Think of December as a mental palate-cleanser. Relax.
Why is this break important? Because after living and breathing your draft for a month solid, the words might start to blur together. You'll start seeing what you meant rather than what your fingers actually typed. Stepping back and clearing your head will let you do that first pass of editing properly. I generally recommend self-editing for the first pass of a manuscript, but especially here, because you'll be able to catch all the embarrassing mistakes that you will subsequently be glad nobody else saw.
It's understandable if you want to get right into editing your NaNo novel right away, but have patience. The results will be well worth it.