Learning a Skill
Skills can be learned when the hero levels up or by reading a 
Skill Book. Skills are automatically available for use in battle when you equip a weapon.
Leveling Up
You will learn 3 (three) skills for each weapon type (sword, staff, bow) when reaching Level 5, 10, 20, 30, 40 and 50.
Skill Book
The most powerful skills of each weapon can be learned by reading a Skill Book. These books are dropped when defeating certain types of Boss.