But I have been using irc and ircd for many years. And if you have to ask HOW to install it. You are better off taking the time to learn more about UNIX and securing the ircd daemon. This is VERY important because very experienced irc hackers with test the daemon for you and might not be nice. Sense most are kids looking to have some fun. At your expense.
Buy the way which ircd was you looking to install. I have installed "Bahamut" on my server?