How do I begin to write a novel?

reposting this from /b/
help me /book/, you are my only hope

Last night in the shower I had an idea for a science fiction novel with religious overtones. I can fill you in on the details of my idea later, but that's not really important. My question is: what are the online resources or books that a noob at writing should look at?

I know I am fairly decent at writing academic essays, but writing fiction is an entirely different story. As a young teen I tried "writing" one or two novels, but failed miserably, especially on the dialogue. How can I improve myself, /book/?

inb4 Elements of Style

First map out the entire story and figure out all the details.
Then just write, you can always revise later. Don't think about how good it is or if it's like any of your favorite authors just write. You don't necessarily need a lot of dialogue, but if you feel it's needed for your story practice your dialogue with some other stuff.