If you can, find a few writing workshops taught by published authors. This will give you insight into what publishers are looking for and certain writing techniques. These workshops can be quite insightful. Writing groups can also be very helpful.
1. First, you have to know how to construct a sentence & paragraph. Without knowing how to do so will frustrate your reader (not to mention your editor).
2. Buy a good quality Dictionary, Thesaurus and Baby Name Book (with as many names as possible) You will need the first two for writing, and the last one to search for character names. Try to read a page (or more) of both your Dictionary & Thesaurus each day. It will help in expanding your vocabulary by knowing the true definitions of words and alternate words with the same meaning.
3. Come up with some ideas - nothing too complex - for short stories.
4. Write out the stories. Edit at least 3 times. Find family and friends (your editors), who can be brutally honest, to read them and give notes.
5. Edit again. Pass back out to your editors.
(You're going through all of this to be sure your work is of high enough quality to send in to magazines. If you start sending in badly written work, they'll stop reading any of your submissions.)
6. Find a few magazines your work could be in. Send your stories in. Look for some contests. Enter them.
7. Don't get discouraged when you get rejection letters - we all get them. Even people like Stephen King & Anne Rice got rejection letters. Just let them make you more determined. If any have suggestions on them, do what they say.
8. Keep sending submissions in until you get into a few magazines. Once you are published you will be able to get an agent. He/she will set you up with an editor. You are then ready for your first novel. Your agent will find you a publisher.
P.S. If you have a few good short stories, skip 6 through 8 and release them on Kindle & Nook etc... It's much easier and done with much less frustration than the regular method. After you self publish a few short stories, and tighten up your writing, you can start on your novel!
Amazon now offers self publication services for Authors that prints books per purchase, and also offers the book for sale on Amazon.
You need to start writing a lot every day to succeed in the writing career. You will also have to be well informed about the various subjects that you write on. This can be achieved by reading widely. Go to http://www.wikihow.com/Be-a-Good-Writer for more information.