1st to Die question

I am avid reader, my father is a truck driver and wants to get into the Audible Book Cd's. I have been looking on Amazon and they don't have a really good selection. I could always go to the library and find some there but he said he would like to have some of the newer books and he want's like horror, action/thriller/mystery type books. I started thinking about Audible. I know its like $14 something a month, but does that include the books? Or do you have to pay monthly for Audible and buy the books too?
*The book I choose for the topic is one of the authors my dad is interested in along with Stephen King*