"I don't know very much," [Roth] says about how he begins a novel. "I write my way into my knowledge. Then, if I'm lucky, I get a break. That's why it's so important to get started. Because however awful starting is — and it is absolutely awful — when you get into it, when you've got 10 pages, which may take two weeks, then you can begin to build."
Philip Roth, from a recent L.A. Times interview.
I really like that "I write my way into my knowledge" line.
But with a novel, that can be a scary approach (maybe not so scary if you're Philip Roth).