Decide what kind of novel you want to write. For authors who are just starting out, the easiest thing is often for them to write the same kind of book that they like to read. The reason for this is that they have enough familiarity with the structure, elements and types of plots inherent in certain genres as well as an appreciation of what they personally like and don't like in a story. If, for instance, you're an armchair detective who loves to read mysteries and try to solve them before the final chapters, you probably have some nifty tricks up your own sleeve insofar as how to keep your future readers guessing.
Identify the genre of your book (i.e., romance, mystery, fantasy, adventure, SciFi, horror). Even if your proposed book has elements of multiple genres, what many authors don't realize is that the finished product is only going to be displayed on one shelf of the bookstore and that the shelves are customarily segregated by genre. Each genre also has a set of parameters that editors expect authors to follow. In a romance novel, for example, you can't have the heroine kill off the hero by Chapter 3.
Identify your target audience for the novel you want to write. Romance novels, for instance, are read by women. Military novels are primarily read by men. Coming of age novels are targeted to teens and tweens who are experiencing problems similar to the characters in the book.
Survey the competition. In order to distinguish yourself as a writer with fresh ideas, it's critical that you have a thorough understanding of what has already been done. To be a good writer, you need to be a voracious reader. You need to read book reviews and be aware of what's topping the New York Times Bestseller List. You need to ask friends what they're reading and what they think of it. You also need to look at who is publishing some of those books that are similar in theme to what you're writing.
Buy a copy of Writer's Market. This is an annual resource directory published by Writers Digest Books. It not only lists what types of novels various publishing houses are interested in, but also identifies the appropriate editors to contact, what type of submissions procedures should be followed and what their advance/royalty payments are. Be sure to look up the publishers who are publishing the kind of novels you want to write. Pay particular attention to the desired word counts for new manuscripts. If, for example, they are interested in manuscripts that are between 75,000 and 90,000 words and your completed SciFi novel is only 20,000, you'll either have to write a whole lot more or find someone who publishes shorter works.
Outline your novel before you start writing. The best way to do this is to decide on the total word count you are aiming for and divide it by 3. Let's say you are going to write a 60,000 word book. When you divide it by 3, this means that the first 20,000 words are your beginning, the second 20,000 words are your middle, and the last 30,000 words are your ending. If you know that you only have "x" amount of space to devote to Acts 1, 2 and 3, it will keep you from meandering.
Identify whose point of view will prevail in your story. This is usually the hero/protagonist and he needs to spend as much time as possible in every chapter. In addition, he has to have a compelling problem that needs to be solved by the end of the story. If it's a problem that your readers can't relate to or if it's solved by the beginning of Act 2, your readers are going to be disappointed. Give them a ride full of surprises that lasts all the way to The End.
Start writing. Staying the course can be a challenge when you're trying something you've never done before. Therefore, you should set up "x" amount of time to write every single day. If you're working a full-time job or taking care of a family, you may have to get up an hour earlier or go to bed an hour later. You may even find it practical to write on your lunch hour or during breaks. If you commute by train or bus, you can take advantage of this time, too.
Join critique groups. Because writing is such a solitary craft, it's important to let other people know what you're doing so that they can gently push you to complete it. If there isn't a critique group in your community, you can either start one or find one online. Participate in chat rooms with fellow writers. Subscribe to writing-related newsletters (most of them are free) so that you can learn new techniques.
Make a list of prospective publishers when your book is nearing completion. Review their submission guidelines and prepare your introductory materials accordingly. In most cases this will be a professional cover letter (no more than one page) that tells them about your book and about your qualifications to write it. Other editors may request a cover letter plus a sample chapter. Always include a self-addressed, stamped envelope with your correspondence.
Keep excellent records on which publishers you have queried. Nothing is worse than sending the same material to someone who has previously rejected it.
Exercise patience. It usually takes between six and 12 weeks to get a reply to an inquiry. If you haven't heard anything by this time, it's all right to send a brief follow-up letter and query the status.