That's a wonderful change that's taken place, and so most poetry today is published, if not directly by the person, certainly by the enterprise of the poet himself, working with his friends.
I can't tell you where a poem comes from, what it is, or what it is for: nor can any other man. The reason I can't tell you is that the purpose of a poem is to go past telling, to be recognised by burning.
I am grateful for - though I can't keep up with - the flood of articles, theses, and textbooks that mean to share insight concerning the nature of poetry.
Besides the actual reading in class of many poems, I would suggest you do two things: first, while teaching everything you can and keeping free of it, teach that poetry is a mode of discourse that differs from logical exposition.
If we ask a vague question, such as, 'What is poetry?' we expect a vague answer, such as, 'Poetry is the music of words,' or 'Poetry is the linguistic correction of disorder.'
For though we often need to be restored to the small, concrete, limited, and certain, we as often need to be reminded of the large, vague, unlimited, unknown.
Even if you walk exactly the same route each time - as with a sonnet - the events along the route cannot be imagined to be the same from day to day, as the poet's health, sight, his anticipations, moods, fears, thoughts cannot be the same.
I must stress here the point that I appreciate clarity, order, meaning, structure, rationality: they are necessary to whatever provisional stability we have, and they can be the agents of gradual and successful change.
