I need to find a new job. How do you keep the fact that you're looking/have interviews quiet?
Also - as more than one person has said that supervisors have "blocked" job hunts in the past, what could I put on applications where it asks "may we contact current employer? why not?"
and what about reason for leaving? Would "not a good fit" be ok (I've worked for employer for over 8 yr, but the location I'm currently at really, really isn't a good fit)
When I've job hunted while employed, I never told anyone. Never, ever, use your work computer or phone for job hunting. (You probably know that, but it doesn't hurt to repeat it.) Take cell phone calls away from your desk if you can.
When I had interviews, I just told my boss I needed time off for an appointment. No need to say what kind--most of my bosses have never cared why I was off, they just wanted to know as much in advance as possible.
For your second question, I've put "no, do not contact," and "Employer frowns on employees seeking other employment." That should be enough reason. If they bring it up in an interview, I've just said my supervisor could be contacted as a reference if they made me a job offer. But only after the offer was on the table. Most companies should understand this.
Please, please, please, do not put "not a good fit." This opens the door to the hiring company wondering if it is you that is not a good fit, i.e. there's something wrong with you as an employee. Better to put something like, "In the eight years that I have been with XYZ Corp., I have moved from Production Assistant to Production Supervisor to Production Manager. I feel that I have advanced as far as I can here, and am seeking new opportunities to utilize my skill set," or something like that.