to get started. you need one of these. this is my bible. if you write literature for adults im sure theyre is an equivalent. not sure the name though.
it tells you the address and email of every publishing company. it also tells you what kind of books they are looking for. then you have to send a query letter to the company, usually by mail. sometimes email. theyre are very strict rules when sending these query letters and you have to follow it to a T. most of the time, you have to send out dozens and dozens before you get a reply. then you send your manuscript. if the editor reads it and likes it and you get very lucky, you get published. and you could only send out one query letter at a time. its frowned upon to send out more than one at once. but ya get the book, that's step one.
and remember I think JK Rowling was denied over a hundred times before someone decided to published Harry Potter. so keep trying. and keep writing.