Brake grinding

About two weeks ago, my buddy put new brake pads on the front of my 1997 Toyota Camry. Everything was running smoothly until I pulled out of my driveway yesterday and started noticing a profound grinding noise coming from only the left front tire-- the right is still fine. What I find strange is that it does not make this grinding noise all of the time; it does not grind when I am at low speeds, accelerating, or braking. The grinding occurs mostly when I am coasting, and is at its worst when I am turning right. Braking is not an issue, the car still has no problem coming to a stop and does not pull to one side or the other. I have not driven since the problem was discovered. I am not what you would call car-savvy, and while I could pop the tire off and try to do it myself, I have a fear that I will not be able to put it back on once I do so, but if I go into a shop to get it checked, I don't want to get overcharged and look like an idiot.

I have a feeling it has something to do with faulty installation, but I am not entirely sure.

Thanks for your help.