There are a couple different buses. The uax bus runs every 15 minutes from the employee lot (Auckland). It begins leaving that lot at :07 after the hour and every 15 min after. From the auckland stop to gate F12 is never more than 10 minutes. The bus stops at F12, e2a, b4, and c5.

The entrance to the employee lot is at the corner of mt prosect road and touhy avenue (the northwest corner of the airport). There is a pizzeria in des plaines called 'barnaby's' that is just down the street from the entrance to the employee lot. Not only is that pizza awesome, it can give you something to mapquest and get a general idea of where the entrance is.