Hit the first milestone today - 5000 words down, 45000 to go. I usually get a lot more done on the weekends, so as long as I can get my minimum -1667 - on the weekdays, I don't see any trouble finishing on time.
One of my favorite memories of the one novel I finished was the part when I felt like the characters began to take on lives of their own. For a wonderful few days, I didn't feel like I was writing the story, I was just transcribing it as it played out. I haven't gotten to that point yet with this novel, but I'm looking forward to it. I haven't plotted the story at all, but I'm starting to get flashes of interesting places that it could go.