World Christian Community Meditation
Christian Meditation (Ireland)
New Pilgrim Path (Ireland)
Jean-Marie Gueullette OP, Petit Traité de la Prière Silencieuse (terrific overview, great advice and lots of uncommon common sense; translated by your humble servant, and given a new title: How to sit with God.
Henri Le Saux (Abhishiktananda) Prayer (simple, immensely deep, inviting; English)