What are some skills that a medieval knight have to know?

How to effectively use a variety of weaponry and shields in combat, horse riding, tactics, etc.

He would also be expected to be able to recognise his brother knights by sight, distinguish, at a glance, between the various lords of the land and determine their relevant 'rank' (who has more respect in the eyes of his lord, etc), must know the laws of the land and the code of chivalry and be expected to uphold them at all times.