I know a lot of people say when it comes to brakes, find a garage you trust etc. but I look at it the other way that I can only be 100% confident if I've done it myself.
Also, when changing pads / discs, I will set aside a whole afternoon and do a minor refurb while I'm at it. Rub down and clean up the hubs and callipers, grease sliders, clean seals etc. etc. I'm sure most garages would spend the extra time if you asked for it, but I doubt they bother normally.
Once you've worked through the process once yourself, you'll never go near a garage for pads/discs again!