What kind of questions do they ask on the polygraph? Do they ask about past work history, criminal records, or drug use? What do they concentrate on? Can you ask the examiner clarifying questions? I don't have anything to hide but just being hooked up to some machine makes me nervous.
I was hooked up to a polygraph for the first time very recently, and it was WAY more relaxed than I thought it would be. I am sure every test administrator is different, but mine was very non-confrontational throughout the test.
You will most likely begin the exam by being interviewed without the machine's analysis. These questions will cover everything you'd expect (stealing, drinking, drugs, driving history, miscellaneous crimes, etc.) and there will probably be a lot of them. You will be permitted to elaborate and/or ask for clarification on any of these questions. Next, the admin (still without the machine) will narrow down his questions and will phrase them in a way that will allow you to answer with only "yes" or "no." For instance, he or she might ask during the initial interview without the machine, "Have you ever stolen from an employer?" If you said, "Yes, but only once and it was just a pen," the admin will then rephrase the question as follows: "Besides the incident with the pen, have you ever stolen from an employer?"
After you've given the admin "yes" or "no" responses to the rephrased questions, you will be hooked up to the machine and asked the exact same questions you just answered. In fact, you will be asked the questions multiple times.
I know the unknown can be unsettling, so hopefully this overview puts you at ease. Obviously, your experience might differ from mine, but perhaps it will be equally as "pleasant." The questions are not tricky or surprising. If you've ever filled out a background investigation form before, you've already seen most, if not all, of the questions you will be asked as part of the polygraph exam.
My advice, clarify everything you need to upfront and stick to your guns for the rest of the exam. You will do fine, especially if you truly have nothing to hide, so just try to relax. I am sure my admin thought I was crazy because I just sat there smiling as I imagined him playing solitaire on his computer the whole time instead of looking at my readings :D
Best of luck to you!
I posted a few times on here about my experiences.
Here's a thread for one of those: http://www.firehouse.com/forums/t117955/
Hope it helps.