"Legitimate" publishers are taking a beating in the market due to e-books and the new "Create Space" type publishers. These on demand sources have really taken a huge chunk of the author's market because writers make more money this way than from "Legitimate" publishers.
That being said I did read about a woman who published her e-book on Kindle and after she reached a huge following she was approached by a "Legitimate" publisher. If you are using that word because you believe the branded publishing house will help your sales then you should know that doesn't mean you'll make more money than you would by taking advantage of the incredible resources available to authors today.
Another article I read, a blog post really, had the author comparing the money he'd made from his publisher versus his e-books. He said that if he could go back in time he would have published all of his work exclusively to Kindle. They pay between 65% and 70% i believe of your cover price, and you choose the price! That's huge! No publisher can touch that!
Now, if you have your heart set on a book deal then you would have to follow in the footsteps of the most famous blogger online Julie Powell. You can read her old blog here http://juliepowellbooks.com/blog.html .
She didn't start writing to get a book deal, she started writing to complete something separate from her life. That being said, it was about being consistant, gaining a following and following through every day. That's how she did it. I have always held to the philosophy that if you want to accomplish something and you don't know which way to go, then follow in the footstps of the person who has done it. You will surely reach your destination if you follow someone who already knows the way.