I'll tell you the one thing I really wish I'd done before I typed one sentence for my first novel: UNDERSTAND THE BASICS. Things like basic grammar, punctuation, point of view, and tense. If you're lucky, maybe you already know all this, but if you don't, I'd very strongly recommend looking around this forum for as much info as you can find. Understanding the basics won't keep you from writing total crap at first, but it will give you a solid place to start improving from.
Honestly, you shouldn't be thinking about publishing right now. The first draft of your first novel is simply not going to be publishable, no matter how talented you are. You will have to write A LOT before you start producing decent quality work, which is where the saying 'the first million words are for practice' comes from (for me, a million words was quite an exaggeration; I started writing some good stuff after about 150,000 words of practice. But you get the idea). This doesn't mean you won't revise your first novel into the next best-seller, but thinking about publishing at this point is getting ahead of yourself.
As far as structuring your time, do whatever works for you. I've never structured my writing time, and am working on my third novel in twelve months. When I was first starting out I wrote when I felt like it, and didn't when I didn't (this is still pretty much what I do). I've always thought that if you're truly a novelist, you won't have to force yourself to sit down and write a novel. You enjoy writing, so you'll end up doing it (editing, however, is a whole different matter, lol).
Oh, one last thing. Don't worry about following whatever 'rules' you may hear about writing (other than grammar rules, of course). Write the story you want to write the way you want to write it, and only change things if YOU don't think they work.
Good luck and have fun!