This is my personal favourite from two great scholars on Christian education and Christian spirituality.
Casey. Michael, 1996. Sacred Reading: The ancient art of lectio divina. Liguori, MO: Liguori/Triumph
An indepth study of lectio divina and includes patristics lectio and their spirituality.
Pennington, M. Basil, 1998. Lectio Divina: Renewing the ancient practice of praying the Scriptures. New York, NY: The Crossroad Publishing Company.
A good introduction to lectio divina. Pennington is one of the few who reintroduced modern Christians to this ancient practice.
Guigo II, Trans Colledge, Edmund and James Walsh.1979. Ladder of the Monks and Twelve Meditations.Kalamazoo. MI: Cistercian Publications.
The Ladder of the Monks is about lectio divina. Guigo II is a twelve century monk who taught lectio divina. I was introduced to him and to lectio divina by James Houston, emeritus professor of spiritual theology, Regent College, Vancounver in one of his courses in Singapore.
Peterson, Eugene H.2006. Eat this book: A conversion in the art of spiritual reading. Grand Rapids. MI: William B. Eerdmans Publishing Company. p.90-117.
A good chapter on lectio divina. In fact the whole book is worth reading. In actual fact the whole series of conversation by Peterson is worth reading (Christ plays in ten thousand places, Tell it slant, The Jesus Way and Practice resurrection). The series is a definitive summation of his life work on spiritual theology .
a good workbook for those who are not familiar with lectio divina but will like to try it.