I need to publish a book. please help.?

[art]

Yes I am fourteen. And yes I feel mature. I don't consider myself the coolest person in the world but I don't fool around like most teenagers. I take things seriously. Laugh at me all you want but I'm serious about writing a book. I'm good at it and all I'm trying to do is write from my heart. I'm not trying to write a book to be noticed. It doesn't matter what age you are. As long as you are good at it and you have faith in your self. I'm determined to do this. I just want to know how much it usually costs to publish a book and how you find a publisher and how you choose the cover of your book. I want to know how publishing a book really works. Please don't write negative comments because I will understand where your coming from but just because I'm thirteen doesn't mean I'm not really good at writing. Like they say, "don't judge a book by it's cover."