Read as much as possible, checking books out of the library or borrowing them from friends to avoid having to pay for them. Most of the books you read should come from the same genre as the novel you intend to write. If you read voraciously from your intended genre, you will learn which of your ideas are genuinely fresh and original and which are repackaged cliches. Read some books from outside your intended genre as well, as melding together the best elements of two separate genres can breathe life into your novel.
Check out books on the craft of writing from your library. Every author has a different technique for writing, from Stephen King's tendency to eschew outlines and extensive notes to Jack M. Bickham's habit of writing key scene information on index cards before beginning his novels, and no one book or article will be able to give you all the options you have available to you as a writer. You should read several books on the craft to get an idea of what methods will work best for you.
Write a vague description of what you want for your plot. It doesn't have to be an outline, as not all authors use outlines, but you should have some idea of where you want your story to go. You might deviate from this description as you write, but without some idea of your eventual story destination, you may find yourself bogged down 50 pages into the book or discover that your novel idea only has the content to sustain a short story.
Jot down the basic personal history, goals and motivations of your major characters. This is particularly important for your protagonist and antagonist. Your protagonist's attempts to reach her goal will drive the action of your novel, and your antagonist's motivation for stopping her from reaching that goal will transform your story into an epic struggle.
Write every day. Aim for a specific goal, such as writing a certain number of words or writing for a set period of time. However, don't give up the day for a loss if you don't have time to write 500 words. Simply write as much as you can and try to make up for it the next day.
Change your technique if you find yourself getting stuck. If you've been outlining rigorously, put your outline away and try to deviate from your plan. If you've been writing freeform, outline your next few chapters. Shift the point of view to another character for a chapter or two to see if you need to experiment with your viewpoint. Reread your draft to see where you got stuck and rewrite that scene in a way that makes the story feel more alive.
Put your draft away for a month or two after you finish it. If you try to revise it too soon, you may find yourself being too easy or hard on yourself. A break will allow you to come back and revise it with a more distant, analytical eye.
Ask a friend to read over your rough draft for you. Take his advice seriously, as he has an objectivity in reading your novel that will allow him to see whether a character you hate needs to be more prominent or a scene you love needs to be abridged in order to improve the plot. However, not all of his suggestions will ring true with you. If his advice seems sound, take it into account; otherwise, follow your instincts and leave your draft as is.
Look for online market guides to find out where you can publish your novel. While some of these market guides charge a fee, others are free. Note the names of some publishers who publish books of your novel's genre and length and who pay royalties you find acceptable. If you want to submit your novel for free, look for publishers who allow electronic submissions.
Read books by your preferred publishers to make sure your novel would be a good fit. Some publishers who sell the same genre of books have wildly different preferences. For instance, some romance markets will only publish erotica, while others will not accept novels with graphic sexual elements.
Submit your novel, following any formatting guidelines on your chosen market's website.