Okay, let's say I finish NaNoWriMo, finish my book, edit it, polish it, and publish it. What's the best thing I can do in order to drive readers to it?
Write another book.
No, I'm not being a smartass. The best way to drum up readers is to get another book out there; while you want readers finding your first book before your next is available, the numbers with multiple books available work in your favor. If you have more than one book in distribution, the more likely it is that readers will take a chance on you.
There are a lot of things you can do to publicize and market yourself, definitely. Make use of social media without being an attention whore about it; send out advanced reader copies; solicit legitimate reviews (and don't take offense at the bad ones. Everyone gets bad reviews...and never reply to a bad review someplace like Amazon. It freaks readers out.)
But mostly, you need to build your audience, and the best way to do that is by getting your next book out there.
My two cents.