About gnome configuration files

[vineesh kumar <vineeshkumarpv gmail com>]

Dear all,
  i am a newbie to this list.
   I am trying to write a program,(or a shell script) which on
installing changes all the locale data to Hindi(an Indian language).
But the problem is I can't find on which configuration files the data
is written in user's home.
I configured the layout using the add panel utility and i can switch
between us kbd layout and hindi kbd layout. but I want to know on
which files these data is written.
The datas i need are:

1)where is the default session details is written
2)where is the locale data written
3)where is key board layout data is written
4)How can we add the kbd layout switcher to the panel and how can we
add another layout to tha switcher without using the gui tools

 help me
regards
   vineesh