Ian Russell's Village Carols site is here:  Village Carols,  though as I said it's not been maintained in some time.

Wyrd Sister makes a very good point; this is a living, local tradition and it is important not to tread on peoples' toes and spoil it for those to whom it principally belongs.  If you do want to go, it's probably best to do so early in the season, and if possible speak beforehand to someone who knows the place, so as to be reasonably sure that you won't be crowding the locals, and have an idea of the way things are done.

I've been a bit torn about compiling a local listing; it's an important tradition and should be recognised, but "folk-tourism" is an ever-present danger.  I don't usually go myself, so I'd have to talk to quite a few people first to be sure that their views on it were properly taken into account.  There may not be time this year, but I will try to sort out something sensible if I can.