Right now I'm about halfway finished with my first attempt at a novel. I have a little more than 42,000 words (about 76 single-spaced MS Word pages, including page breaks between chapters and title page). I'm into chapter 16 so far. My goal is 80,000-90,000 words total.
This is the only project I'm actively working on. I have a few ideas on the back-burner, but I know if I start them all at once I'll never finish anything. Sometimes when I get burned out on my current story I'll write a scene for one of my other ideas, but only one.
I don't have a set work environment or time. I've heard it helps, but I'm a mom and I work, so I carry my netbook around and write where and when I can. I found out on a family vacation (and I mean family; there were 32 of us) to my grandma's house that I can't work surrounded by a mass of people, but a few are OK as long as they don't talk to me. Ipod helps, even though I use it more as a noise-blocker and less to listen to music.
I think you'll find we're all over the map on that question. Why don't you join us in the Novel Support Group (NSG) under groups? We set goals for ourselves and sometimes exchange chapters for comments/critiques.
As for me, I currently have quite a few projects--possibly too many. I have one completed novel, for which I'm trying to find an agent. I have another (sequel) completed in draft. That one is sitting for a while before I go back for revisions/polishing. I've got about 43,000 words on a third, completely unrelated novel, an outline for a fourth (sequel to the first two), and fifth (unrelated novel) still in the idea stage. In addition to those, I've got one flash, three novelettes/novellas, and I just started another short story today (instead of working on my current novel).
Since I'm still chained to a desktop computer, I pretty much always work in the same place. Of course, I have been known to actually use pencil and paper. As a matter of fact, the first draft of the completed book was written that way. So was the first (bad) draft of the second. It helped me slow down and think about what I was writing when I first started out.
I typically write a little throughout the day. But the hour or two after I clean up the dinner dishes are the most productive, usually--unless I'm really tired, that is.
Meanwhile I returned to an old abandoned project, for which I had a complete rough draft (about ten thousand words), but in which I had to write up and insert a couple of fresh scenes. Writing is always easier when you're rephrasing something from a document in front of you. But in this, at least, I know what happens and why. I worked on that this morning, right before I went online and came here.
I'll probably get back to both abandoned novels at some point, I think...
Every now and again I'll go into a fit and stamp out 100k words in less than a week's time. It's never gotten me anywhere, but I always have the time of my life during that week.