Go to your local library or bookstore and get a book on the writer’s market. The one that I used was called Jeff Herman’s Guide to Agents, Editors, and Publishers. You want to find the most updated version of whatever book you get, because you are going to be writing to the people whose addresses are listed inside, and you want to make sure they are still working at these places.
The book you get will tell you that to get a publisher to look at your book, you must first write them what’s called a query letter. This is a one page letter describing you, your book, and why a publisher would want to buy this book from you. Just to let you know, I sent out several hundred of these letters before a single person ever asked to see the book I was trying to sell.
Some people say if you get anyone to look at your book at all, you are lucky. I believe that luck is 95% preparation and 5% opportunity. So basically…you have to make your own luck.