D&C 88

In the very early days of the Church, the Lord instructed -

"And again, the order of the house prepared for the presidency of the school of the prophets, established for their instruction in all things that are expedient for them, even for all the officers of the church, or in other words, those who are called to the ministry in the church, beginning at the high priests, even down to the deacons—
128 And this shall be the order of the house of the presidency of the school: He that is appointed to be president, or teacher, shall be found standing in his place, in the house which shall be prepared for him." (Doctrine and Covenants Section 88:127 - 128)

Of of the president -

"...he shall be first in the house of God, in a place that the congregation in the house may hear his words carefully and distinctly, not with loud speech." (Doctrine and Covenants Section 88:129)

It is clear the Lord wanted his priesthood leaders to receive instruction in their ministry and duties. I see this as the very beginning of what of now has evolved into priesthood and priesthood leadership meetings throughout the Church. For -

"...as all have not faith, seek ye diligently and teach one another words of wisdom; yea, seek ye out of the best books words of wisdom; seek learning, even by study and also by faith." (Doctrine and Covenants Section 88:118)

And also -

"Appoint among yourselves a teacher, and let not all be spokesmen at once; but let one speak at a time and let all listen unto his sayings, that when all have spoken that all may be edified of all, and that every man may have an equal privilege." (Doctrine and Covenants Section 88:122)

Of these initial meetings, President Brigham Young said -

"...the members of that school were but few at first, and the Prophet commenced to teach them in doctrine to prepare them to go out into the world to preach the gospel unto all people, and gather the select from the four quarters of the Earth, as the prophets anciently have spoken. While this instruction prepared the Elders to administer in word and doctrine, it did not supply the teachings necessary to govern their private, or temporal, lives; it did not say whether they should be merchants, farmers, mechanics, or money-changers. The Prophet began to instruct them how to live, that they might be better prepared to perform the great work they were called to accomplish." (In Smith and Sjodahl, Commentary, p. 567.)