Do it! Writing novel in a month is hard work. The first one I did was rather like a gauntlet. You have a goal to get to the end while you are being hit by other priorities and your own doubts. Still, you forge ahead. When you are done you have a great feeling of accomplishment, and a well-deserved one at that.
Be prepared to hate your own work. It's a phase. Don't take it too seriously. You will vacillate between hating the novel-in-process and rehearsing national television appearances. Don't take that too seriously, either.
The first time I observed Nanowrimo was a few years ago. I set the goal of writing two thousand words a day, with the eventual goal of 50,000 words for a complete novel. I mentioned something to a co-worker and soon it became a thing where I was asked how many pages I had written so far and I would go into this explanation about how reformatting changes that and I wrote two thousand more words. "How many pages did you write?" came the daily reply. Then I would break down and tell them.
Let me tell you what works about Nanowrimo. You get the novel written. The process taught me valuable lessons as a writer about turning off the internal editor. When you have that much to write in a given time period, there is no time to second-guess yourself.
Part of the writing process is to recognize the different types of thinking that go into a creative writing project. One part is the raw exodus of feeling and idea from your mind and soul. The other is to review what you have written, examine it, and to change parts of it. Yet another is editing for grammar and spelling. Still another is to contemplate the pieces that are missing or are duplicative. Each part takes another area of the brain to complete. It cannot be done simultaneously. Recognize that and consciously decide which task you are doing now. Then do that task.
Let the novel surprise you. Write only for yourself. You really need to be interested in the book you are writing. The process of writing the book should be fun for you. I wrote and produced a play called Felony about twelve years ago. The primary regret that I have from that process were the compromises I made to pander to my idea of what would be popular.
So be brave, braver than I was back then. Write it, feel it, be it. No compromises.
See the website for NaNoWriMo
See community events around NaNoWriMo in South Carolina.
See Wikipedia's entry on NaNoWriMo.