The Spiritual Exercises - The Ignatian method of prayer uses visual imagination to draw nearer to God. Intended for spiritual directors or retreat masters. Elder Mullan translation. Also available in RTF and pdf. - http://www.ccel.org/ccel/ignatius/exercises.html
Letter on Obedience - Probably the best known of St. Ignatius of Loyola's letters. Written to members of the Society of Jesus in Portugal. - http://www.cin.org/jesuit.html