What are the security measures I need to follow if I implement website in intranet?

Question

Hi Friends,
Like this only but not in joomla and less than 10 users.We are going to give the demo of our web application on intranet and also we may implement in intranet only.So the concern is

1. The source code and database needs to be secure(i.e.Not easily readable by clients)
2. What are the security measures I need to follow in this situation?

Hint:we are going to implement on the windows server with xampp only.

Question 2:
I am not very well known to configure how to implement intranet site.What are the configuration I need to change in xampp?Please give me suggestion and valuable tutorials on this.
Thanks in advance.