yeah, concept id right on that, if the pads that were put on were cheap or even moderate priced pads they may have metal shims on the back and these make the pads squeak alot, as he said hawk makes great pads and rotors they are quiet as a whisper but they cost a pretty penny and usually cannot be found at your local parts store. autozone gold and max pads (the gold that are ceramic) have a nitrite rubber shim, i have these installed on my car max on front ceramic golds on rear with their gold rotors and my brakes make absolutely no noise at all. these can easily be found at most autozones or ordered quickly for you and pads will have a lifetime warranty. concept did also mention air in the lines which can do this as well. however you would notice your brakes would not feel right if there was air in the lines. it cannot hurt to have them bled anyway.
if you are unsure of how to properly work on brakes swing it by a reputable shop and have one of the techs come ride with you and show him/her what it is doing. a reputable shop should be willing to do this as they want you in good shape. where did you originally have the pads installed? and how much did just the pads (not including labor) cost you? this can help us determine what brand and what quality you had put on. cheap pads will always squeal. the cheap ones we sell at autozone are bad about that with the hard metal shims. the brake lube helps it some but they still occasionally squeak but the better quality ones are quiet and great pads, i always recommend people get the gold (ceramic if the option is there) or max pads as they are leaps and bounds better than base pads. its worth it to spend more on brakes as they can be the difference between stopping before a wreck or being in one. the max and gold ceramics can handle very spirited street driving styles like i have.