I'm addicted to Yahoo Answers recently, mostly answering obscure medical questions and telling new writers not to pay to be published. Today a young writer asked for general advice, and this is what I said:
Read. Read extensively. Read great books, not just ones you know you're likely to enjoy. Don't be intimidated. Get in there and read the greats. Read the big award winners. Come up with your own opinions about who's good and who's not. Reading is the only way to develop the rarest tool in the writer's toolkit: voice.
Notebook. As in, carry one around with you all the time. Keep it next to your bed. Take it into the bathroom with you when you shower. You never know when ideas might occur to you. Just don't try to write and drive at the same time.
Ideas. Skim through your notebook once in a while and write down the big story ideas. Play around with combining them. Novels are big. Huge. They usually need a few ideas to support them. You'll be surprised what happens when you combine ideas that don't seem to fit together at first blush.
Theme. This is the hardest thing to understand in a novel, because it's what's going on in the writer's head. What point is he or she trying to make? Sometimes you don't know until the last page. This is what the writer feels is true about being human. Start pondering what you believe.
Outline. The one mechanical element you need. Because novels are big. Write down what you can. If you know what comes next your creativity can be free to work on dialogue and description, and you won't always be panicking about the next scene.
Structure. This is what holds up the story and gives it shape. In the western world, there are paradigms for structure. Christopher Vogler's _The Writer's Journey_ is an excellent resource for learning structure.
Good luck, and enjoy.