IRC is short for Internet Relay Chat. To access it you'd need a client to use it. mIRC could be an oppertunity. I use vIRC.
Emuchina is apparently another emulation site but very large.
www.emuchina.net has a lot for download, but have an IRC channel as well it seems.
TOSEC...well I can't quite remember, but I know my Amiga has problems with the way too long filenames when extracting zip files in the format there.
http://tosec.retrogames.com should give you some insight.