The main chatclient I use daily is WeeChat, and to help others get started with this client, at some point I wrote FiXato’s Guide to WeeChat.
It's not as up-to-date as it used to be perhaps, but it should still be useful to some of you.

As I've spent quite some time on IRC, I've often seen the question "What is an IRC bot?", or "How do I get an IRC bot?". As such, I wrote FiXato’s Guide to IRC Bots. For the Chat4all IRC Network I wrote a separate version with some network-specific information: FiXato’s Guide to IRC Bots on the Chat4all IRC Network.