John Wayne Airport, where's the employee parking lot?

My job is inside the airport, and up until now I've been taking public transportation to work. Well, I've heard that it's possible to park outside the employee parking lot on Main Street, and take a shuttle to work, thus not having to pay for parking.

My question is, where is the employee parking lot, or where is it I can park, and take the shuttle? Where is the shuttle bus stop? And how long does it run?

Thanks