Do you have a "bible"?

I am not referring to the stories we commonly know as “bible” – I’m using the term to describe a book which gives you answers/grounds you/provides guidance. Is there one particular book or author you keep returning to?

I don’t believe in God, but I do have a book I read when I need some help understanding myself. It provides answers on relationships, and its tone is soothing, to me.

PS: If your “bible” is, in fact, a bible – feel free to say just that.