Hone your language skills. A writer needs a well-developed sense of style and an excellent grasp of language. Utilize proper grammar and expand your vocabulary. Make note of the differences in the ways that people speak and the ways that they write.
Hone your writing skills. Write in a wide variety of styles, voices and genres. Practice creating dialogue, description, characterization, worldbuilding and plotting as mini-projects. Focus on those areas that need development.
Hone your literary skills. Literary devices and figurative language are essential to fiction writing. Novelists know how and when to use them, and they study the ways they have been used by successful writers. Read stories written in many different genres from different time periods and places.
Participate in writing events. Many writers benefit from working with those who share their goals and interests. Join a workshop or a fiction writing class to get feedback on your work. Network with other aspiring writers in online forums or communities such as Critters.Org.
Force yourself outside of your comfort zone. Write about things you don't necessarily find interesting and talk to people with whom you wouldn't ordinarily speak. These experiences will improve the scope and quality of your writing.
Study how the publishing industry works. Many new writers operate under numerous misconceptions and become disappointed with the business end of writing. Learn about potential scams by reading blogs like A.C. Crispin's Writer Beware blog (accrispin.blogspot.com).
Learn what is expected of you when you look to sell your writing. Read the blogs of agents, published writers and first-time writers who are in the process of being published. Some well-known blogs of this type are Miss Snark, Lit Agent X, Pubrants, The Rejecter and Editorial Anonymous.
Become familiar with the process of submitting your work to agents. Learn agents' requirements for submissions. Think about which agencies you would like to represent you, as well as the kind of novels you need write to convince them to accept you as a client.
Practice writing query letters even if you do not yet have a manuscript ready to sell. Your query letter should pitch your story and introduce you as the author.
Build up a body of work. Write as much as you can as often as you can. Work on many projects rather than focusing all your time on one single story. If you have completed a manuscript, put it aside and work on something else. You will then have several projects available if an agent asks to see more of your work.
Built up accomplishments and credentials. Submit stories to magazines or ezines and other online publications. Enter writing contests. Prior publication will be of interest to an agent, although self-publishing with a vanity press is unlikely to impress.
Create a professional blog or website that describes your credentials and gives readers an idea of the kind of writer you are. Network with other writers and build up a good reputation.
Choose your best manuscript and submit it to agents. Use your query-writing skills to market the story and generate professional interest.