Looking for a traditional publishing contract?
You need a literary agent.
A good agent will work hard to sell your book to a publisher and negotiate a bigger advance and better contract than you would for yourself.
What’s more, many editors – particularly those at the biggest publishers – prefer working with agents. They know that agents filter out work that isn’t publishable by vetting the author’s book concept and writing in advance. They also know that agents speak the lingo and understand the process — they don’t have to spend time educating them on what to expect.