I get asked this question often and I wanted to address everyone's questions in one blog post, let's see if I can. First of all, you have a great story idea, now you must write it. For some people this is the easy part. For me it wasn't, it took alot of commitment and focus to make this happen. One thing that helped me alot is this book by Dorothea Brande, called "Becoming a Writer".
Ok, so say you found your muse and you wrote your first book. The next step is rewriting, editing, and joining a critique group. This is a very intimidating part of writing a book. I found out the hard way that I rewrite a book until it is almost unrecognizable from the first draft. It's a little frustrating when you first learn this about yourself, but just know that many successful authors have the same process and it is very worth it. Editing requires help. You can't edit your own work entirely by yourself. You are too close to the story and you know what you think it says, but you don't know how other people will read it. This is why you must have critique partners. Here's a cute video by Jackson Pearce about why critique partners are important:
There are some great online writer's groups to help you with this. Our own MormonMommyWriter's online yahoo group is a good place to get feedback. Also, joining ANWA, a writer's group for mormon women, has really helped me in this respect. They also have online meetings if you don't live near a chapter.
Ok, let's say your book is done and in perfect order. The next step is deciding what kind of publishing you want to do, traditional publishing or self-publishing. Check out this link to compare and contrast the benefits of each. If you decide to go with traditional publishing you must decide if you are going to first look for an agent. Here is a link about agents. Next step is to write a query letter. This is a link to a google search about writing query letters to agents. Say you want to send a proposal directly to a publisher. Here's another link to a google search for that.
So now you have a query letter or a proposal, how do you find out who to send it to? Visit http://www.agentquery.com/ for a list of agents in the genre you are looking for. Also, your best resource for any of this is a book called "Writer's Market". You can also go to WritersMarket.com.
The next step in all of this is to remain positive and continue to educate yourself on the craft of writing. Here's a few books to help:
Getting published is not for the faint of heart, but you can do it! Just keep at it, you only fail if you quit!