The only dumb question is the one not asked.
IAC - Idle Air Controller. It's one of the sensors in the throttle body, diamond shaped.
The throwout bearing is something like 50 bucks, I have no idea what you're going to be charged for labor. I've also heard that the noise is caused by a worn fork, but I'm not sure about that. I know that I've got a new throwout bearing in one of my Neons and it makes the same noise, so there might be some truth to it. I'd ask your dealer.