If you suspect the pads are not releasing properly, also be sure to remove the chrome pad retainer clips from the caliper brackets and clean any corrosion that might be hiding underneath them (a square file works well for this). Rust here can push the clips against the pads and cause them to bind.

Also clean the clips with sandpaper. Here in Minnesota, I use anti-seize on all these surfaces, once cleaned, to keep the pads free. Road salt really does a number on brakes.

Also be sure to check the caliper pistons for smooth operation - if they are difficult to push back in, it may be time for new calipers.