I want to make one for my Runescape client, but have no idea where to start. I took a look at the sources on PSC, but they're all outdated and I've got no idea how to update them. So, please, if you know what to do let me know
I also would like to know this. I've found VERY outdated ones, and theres no tutorials, i've tried google already =/.
You should look into "sockets" and sending / receiving data with them. http://www.xtremevbtalk.com/archive/index.php/t-76863.html ^ That should also help you.
I was going to make an IRC bot awhile back but kinda stopped just after starting it, you can have the source to it. It should help you to a certain extent.