I'm guessing it just means that once you've stopped using the brake, apply the handbrake before taking your foot off. If you're coming to a stop on a hill and just pulled up the handbrake once you'd come to a halt there's a chance that (if you'd just started rolling backwards) the handbrake won't be enough to stop the car rolling, however if you stop on the brakes, apply handbrake and then foot off the pedal it'll hold fine. As for pulling away on a hill.....use the accelerator and clutch to find the bite, give it a few revs then slowly let the handbrake off.