A very beautiful book in N'ko consists of many simple authentic supplications that a Muslim should daily or occasionally say, based on Quranic and Prophetic texts.
A book in N'ko the five pillars of Islam: The two testimonies, prayer, zakah, fasting, and pilgrimage. All of them are simply handled in detail concerning meaning, proofs, wisdom, and conditions.
A book in N'ko explains the six pillars of Islamic faith: Belief in Allah, His angels, His books, His Messengers, the hereafter, the good or bad predestination from an Islamic perspective.