Plugin development tutorial?

[Brandon Fosdick]

I've decided to write a simple chatbot that lives in a chat window as a toy project. It seemed simple enough and probably a bit of fun too. Unfortunately, I hit a wall when I went looking for a plugin tutorial. "Toby's Guide to Plugin Authoring" appears to be very old, and presumably out of date. Google isn't being very helpful either.

Is there any sort of tutorial or reference that I should be looking at? Is there an existing plugin with good source that I can use as an example?