Lots of people ask me for advice on getting published. All I can really offer however is what happened to me. I wrote my first novel while working full time as a journalist. The first draft took me about year to complete and while it was dreadful (it had characters changing name in the middle of a sentence and had plot holes you could drive an articulated lorry through) it was at the same time a complete novel, something I could work on, fix and improve, which is exactly what I did. I then gave it to friends to read, took on board their comments before packaging up the first three chapters and a synopsis and sending copies out to three literary agents whose names I'd obtained from the Writers and Artist Yearbook.
After a long wait I received a rejection followed by another rejection and then just as I was beginning to lose hope the third agent got back to me and informed me that she loved the book. We worked on the manuscript together for three months ironing out the creases before sending it to seven publishers on a gloomy Friday afternoon in October. By ten o'clock the following Monday morning we had two offers on the table and it went to a bidding war which was not as much fun as it sounds and made my head hurt a great deal.
By the end of the week a deal was struck and the book they bought, My Legendary Girlfriend, was published just under a year later entering The Guardian's original fiction list at number two, and later on paperback publication, entering The Sunday Times top ten bestseller list. If I have any wisdom to offer you from my experiences it would be read often, write frequently and don't give up.