Publish Internal Web Server and Mail Server

hi.i have small network(Domain).and one powerful server ,installed AD and Domain ….,i want to publish one web server on this computer for run Web Application on that without use internet and public IP.any client when try to reach that open the Internet explorer and type address like this:farbodkain.com and then see that Web application.and run mail server either.plz help me to Solve my problem.thanks a lot