There are a lot of online resources. Applescript is very powerful, currently i made a few that... Run cron scripts (daily, weekly and monthly maintenance on my G4), sometimes i turn on my iTunes to AIM that i wrote about 2 years ago... this takes the current song and places it in my AIM away message, along with a nice formating to make it seem like a "Now playing...." I have folder actions to backup files to different partitions (still working out bugs), a custom AIM away message, dependent on who the person is, i can leave specific messages. Scripts to put my system to sleep from my cell phone (phone sends a email that triggers a script from Entourage, that does this or that)... and a few other mini scripts that I was curious about.
Just read up on it, and try to make something, the more you play around with them, the better scripting them you will get. Almost forgot, I made a Bot for AIM. Although it was triggered by keywords, that didn't work to well, because if that word came up in a chat session, it would automatically prompt the user with "Welcome to Urbansory, Please enter your inquiry.... " It kinda freaked a few buddies out, so i turned that one off.