Well it depends what IRCD you are searching for.. If you're looking for one like Undernets' then you can look here : http://www.coder-com.undernet.org/
and dload the latest version of IRCU or get it via CVS , read about it at http://www.coder-com.undernet.org/cvs.php
afterwards you might wanna get GnuWORLD , get it here http://gnuworld.undernet.org/
, you might wanna get this thru CVS too. just put them on you server and read the manuals. For more help join #coder-com on the Undernet Network or post on their section from this forum. You can also find a very nice and useful setup guide on the gnuworld site , here : http://gnuworld.undernet.org/gnuworld-setup/
You might wanna use something diferent from IRCU. A popular , and easy to use is Beware IRCD , get it here http://www.xs4all.nl/~beware3/irc/
For a Quakenet feel to your network you can take a look here http://dev-com.quakenet.org/
, to see their server side applications. Do not ask for help related to the last two IRCDs listed here, on the Undernet forum nor on the #coder-com channel.