Filemanager how do you get it to work??

I am trying to get file manager to work. It does nothing which config files do you need to change for the PHP connection. I think I have told it the right directory I want. As I presume it takes it from the home(public_html) directory. So I set it as /pics/ as this is my default picture folder any ideas? It wont display anything in the file explorer and crashes on upload!