First, you need to make sure that what you've written is what you actually want to publish. Don't send it to a publisher or agent until you've revised it several times, making sure that it's as perfect as it's going to be. Then send a one-page letter explaining who you are and what your story is about, along with the first three chapters or so, to publishers/agents who would be able to publish your book. You're going to get lots of rejections, so don't worry about it, just keep trying. Your agent/publisher will sort out the copyrights, I think.
There's no formula for a successful book. You just have to write to the best of your ability. Don't give up. Keep writing. The more you write, the more you'll improve.
Hope this helps.