Don't overlook the hydraulic system, a network of fluid-filled pipes which carry to each wheel the braking power you apply with your foot. Under the bonnet you'll find a small clear plastic brake fluid reservoir with a high and low mark. Also make sure you have the fluid completely replaced at the intervals recommended in the owner's handbook. Brake fluid absorbs moisture. In time it will become less effective, corrosive and even liable to boil, causing total brake failure.
Disc brakes are more powerful and offer more consistent stopping power than the older-style 'drums'.
But don't be worried about cars with drum brakes on the rear. As most of a car's weight is thrown forwards during a heavy stop, the front brakes do 60 per cent or more of the work. In most situations a good drum set-up is entirely adequate at the rear but it must be regularly checked and properly maintained. To work effectively, a disc rotor must be smooth and true. This is neither difficult nor particularly expensive.