mIRC is free, it just says its a trial. It will just pop up a little thing everytime you open it. If you like mIRC then, I guess use that as a client. If you want a good client, with many features, I use excursion at,
http://excursion.humr.org/ (if you open the download folder, you might notice it has the keygen to stop the popup). This is a script for mIRC, you'll learn about that later. It allows things to be done easier.. IRC is fun, depends on what you're into tho. I'm into warez and stuff like that, hush hush.. So I serve in there all the time, excursion does a good job of that for XDCC, Fserv, ftp (need ftp server for that) and pretty much every other kind of serving. Look up basic IRC commands, use the help, it works. AIM me on DjMinDFreeZ if you need help. If you already know the server, first make your nick, and use the command- /server <server name here>. Example: /server irc.xptech.org . then press enter, it will connect, probably tell you your nick isnt registered, in which case you register it with:
/msg nickserv register <password> <email>
or, shortcut:
/ns register <password> <email>
there's a lot to learn for all of it, but the basics are:
connect to server
list/join the channel(s)
chat......
download if u want (need to learn more commands)
learn
learn
learn
dont get flamed for asking dumb questions
learn
get off IRC
the end.