Learn where Bill's story is weak compared with the facts you know. Describe the power of the polygraph to raise fear if he is lying, and confidence if he is telling the truth. Control questions are tricky business. If lying, Bill will be fearful denying that he took the deposit, but relatively at ease on the less-threatening question of other thefts. You leave Bill alone in the room, which helps focus his mind, while you finalize the questions and their order.
Blood pressure is measured around the biceps.
Sweating is measured at the fingertips. You don't mention breathing, measured at the chest, because Bill might try to control that. You expect to give three tests of ten questions. Each test will take about three minutes. You sit still and do not allow your face or voice to emphasize particular words or questions.