Congratulations on writing your novel. I am not sure how far down the road of trying to get a publisher you are, but here is some advice.
Make sure that the novel is the best you can possibly make it. Revise, revise and revise again. This is essential especially in today’s market where it is VERY difficult to get an Agent or Publisher. If you haven’t done so then I would strongly advise getting a literary consultancy to review your work and make comments on it. I recommend The Hilary Johnson Authors’ Advisory Service. Hilary will match your novel with the right editor . This will cost you, but it is a good investment, because you will get your MS returned with edits where it can be improved.If you have already done this and feel you are ready to approach a publisher then you need to research which publishers publish in your genre. The bookshop or library can help here. Just look and see who publishes other authors similar to you. Many publishers today don’t take unsolicited MS and use Agents, so you might want to approach an Agent first. Either search online for ones that take your kind of work or use the Writers' and Artists' Year Book. Send them what they require and then wait. They take forever though so you might want to approach a few Agents at the same time.
There is lots more advice in Publishing and Promoting Your Book. It also covers self publishing if you decide to go this root. There are also some web sites now where you can pitch your book, or put your work on line and invite reviews and the ones with the best reviews could get picked up by a publisher. There is http://www.marketplace.meettheauthor.com/ and Harper Collins have a site http://www.authonomy.com/
Final piece of advice though, never stop writing, no matter if you keep getting rejection letters, and whilst sending this novel out get working on the next one, and then the next and so on, because believe me you get better and better.
Good luck to you, and you never know, your novel might hit the spot right away. Number one and you’re off…