The everyday rules
Keep left. Overtake on the right. Give way where you are required to, and signal every change of direction.
Do not sound the horn where it is prohibited - near schools and hospitals, and in areas where a demonstration or a gathering is taking place. In many urban zones the horn is restricted entirely.
Carry the documents the vehicle and the journey require, and produce them when asked.
The rules apply to everyone using the road, not only to drivers. Following them is the duty of the driver, the passenger and the pedestrian.