there are generally two types of brake pad noise. one comes from the pads rubbing the disc and is more of a grinding sound. the other, more common, sound is a high pitched squeal that comes from the pads vibrating against the pistons. this is exacerbated by brake dust gathering there.
i temporarily solve this problem on my other car (X doesn't squeal) by washing in there at a car wash. next time i change the brakes i'll put in anti-squeal pads.
you can put those pads on yourself if you're handy and can do a brake pad replacement. otherwise any brake shop could do it.