Setting is important when you're writing your novel. You want to give your reader a sense of where and when the action is happening and draw him or her into the world you're creating. But the setting of your physical writing place in this world is of equal importance. Some have the luxury of an entire room of the house to dedicate to writing. My study houses most of my creative activities, like writing and artwork. Since I worked on art this week it's slightly less cluttered than it's been recently (it helps to be able to reach your art desk), but it still needs a lot of work. And with five days remaining until the start of NaNo, and that fun but pesky Halloween between now and then, I've got work to do.
I have a mini-poster somewhere around here that reads, "Geniuses thrive on clutter". It's a cute saying, but take it with a grain of salt. Clutter disrupts my creative flow, I've discovered. A desk completely barren of anything save the tools I need to do my work is a bit creepy though, so I try to strike a balance. And after all, isn't it said that a clean desk is the sign of a sick mind?
If you do your writing outside the home, your options are probably more limited. At a library or coffeehouse you may want to take headphones to listen to something other than screaming children or Muzak jazz. I did a couple writing sessions at a Starbucks last year during NaNo and found the music terribly loud. I had to make a concerted effort to shut it out, since anything with lyrics tends to disrupt my writing process. That's why I prefer (some) libraries, generally the type which would favour a stereotypical "Shhh!" sign on the librarian's desk. I've been to 'non-shush' libraries and while they're still great places, conducive to my writing they are not, at least when populated by ... disruptive forces. I have a hard time staying in my scene and/or character when assaulted by the periodic sounds of stomping toddler feet and overloud queries or exclamations. I try not to wince too hard.
Your desk at work can be a good place to get some writing done, provided you can do it discreetly and without costing your company too much of your productivity. Even if you don't have a desk you can still work on things, even if it's only to sort out a plotting problem in your head while you work. I once worked at a warehouse job where I carried a notepad in my pocket and composed bizarre songs about how much my feet hurt. I also wrote over 10,000 words of a story during that time, using bits of the warehouse as setting. Stacks of boxed product threatened to topple onto characters while they were running around during an action sequence. And I think I chased them around with a forklift gone haywire. Somehow I never used any of my coworkers as templates for characters in that story. Some of them were quite colourful and entertaining people.
Give some thought to the place(s) you'll be doing your writing during NaNo, and prepare while you have a little time. Because once you start writing, you won't want to be distracted by tidying up. Or that tidying will suddenly become The Most Important Thing (TM) in your entire life and will keep you from writing.