What is the correct way of breathing when doing the breaststroke.

Ziggy is incorrect...The best way to breathe during breaststroke is to let the head follow the spine. When your elbows have reached the line of your eye and have begun to rise your head starts to lift. If you use your high elbows as a hinge for the inward sweep of your hands and forearms, you'll create the leverage you need to use your abdominal muscles to bring your hips forward. When your hips move forward, your chest, shoulders and upper back will automatically lift up. Breathing is usually done during the beginning of the insweep phase of the arms, and the swimmer breathes in ideally through the mouth. The swimmer breathes out through mouth and nose during the recovery and gliding phase. Breaststroke can be swum faster if submerged completely, but FINA requires the head to break the surface once per cycle except for the first cycle after the start and each turn. Thus, competitive swimmers usually make one underwater pull-out, pushing the hands all the way to the back after the start and each turn.
Some people keep their head above water at all times when they swim breaststroke. This is not only difficult and unpleasant, but also dangerous for the spine. Swimming with the face held out of the water puts undue strain on the muscles of the neck and back which can lead to damage of the spine?s interior facet joints.