You should avoid publishers that demand money to publish your book. They are called 'vanity' publishers - the clue is in the name. If your book is good enough, a publisher will publish it, and form a contract with you as the author - you will not be required to pay them.
You have not advised the subject and genre of your book, but the first step is to locate publishers which already publish your style of novel. It's no use sending a thriller to a publisher that issues cookery books, and vicce versa.
Check out your local book shops and find which publishers are suitable, and mail them a brief synopsis of your novel.
Be prepared to be disappointed - any major author will confirm how they were rejected dozens of times before they found a publisher, so dont be discouraged.
You might also want to visit your local reference library, and find the latest issue of the 'Writers And Artists Yearbook' which will list authors' agents - it may be worth writing to suitabe agents, again with a synopsis.
Don't bother sending manuscripst unless invited - it;s a waste of expensive postage, they won't be returned and are unlikely to be read if not requested.
Hope this helps - let us know how you get on.
Remember, you will face a mass of rejections before you get anywhere, that's the way publishing works, so don;t be put off.