My experience in narrative theory is relatively light. I've read Genette's Narrative Discourse: An Essay in Method. It's hardly thrilling reading, but it's very useful. I use a lot of the handier concepts when teaching: it gives those students who are interested a little more precise vocabulary for dealing with point of view / focalization and the relationship of narration to time.
Haven't really sought much more out. What do I need to read to get me up to date?