The best “teaching” about the Eucharist is via the Mass, of course.
However, of the books specifically on this topic, the two that I’ve found most useful are:
1) The Hidden Manna: A Theology of the Eucharist by Father James T. O’Connor
2) The Eucharistic Hymns of John & Charles Wesley by J. Ernest Rattenbury.
Speaking of Wesley, there’s a relevant article:
Anthropology and Transcendence: Wesley’s Sacrificial Eucharistic Theology in Ecumenical Context by Stephan Sours.