When submitting work to a publisher, it is critical you follow their guidelines!
If they accept direct submissions, they will have their guidelines posted on their website. They will all require a query letter, which must be composed according to the standard and will be the most important piece of work you ever write. They may also require a synopsis; an outline; or the first three chapters. Never send more that what they ask and always include a SASE for a response - or you will not get a response!
And be prepared to wait - most publishers take 3 months to one year to review submissions!
"I'm not a failure if I don't make it ... I'm a success because I tried." - Unknown