thank you both James-Anthony and Daniel - very interesting replies and I shall look into what you suggest.
By the way, I managed to get hold of a copy of The Philokalia, vol.1, that Fr. Simon mentioned on the retreat weekend (ordered it through the inter-library loan scheme, which is just brilliant - it's amazing what books are held in various dusty offices in far-flung libraries in this country).
I have a copy of the Sayings of the Desert Fathers, which is awesome. Love it.
In fact, I think I might start a new thread, asking people about their favourite reading matter....