I'm flying from any of the London airports. Any other tips for this route are welcome. We'll walk from April 23 and stop at St. Jean (shame!) and I expect we'll have to bus a few times as we only have 5 weeks.
no airport is particularly near, and Vezelay is not the simplest of places to get to (other than on foot, of course). Easiest is probably to go to Paris, and catch the Avallon train. An obscure station called Sermizelles is the official halt for Vezelay, and there is some sort of shuttle bus service. (Alternatively, walk, as the GR isn't that far away - ca 10km to Vezelay.) You can get the train timetable at http://www.ter-sncf.com/bourgogne/ and the official town site is http://www.ville-vezelay.com/ - they can no doubt give you more info on the shuttle bus.