User's Initialization File
The most reliable way to find our the place of the initialization file on your system is to check the value of the user-init-file variable.
 Configuration Example
For a good example of an init file check out some of the starter kits, like Prelude.
 Debugging the Init file
$ emacs --debug-init
Running the above command will enable the Emacs Lisp debugger for errors in the init file.