Ian,
I went to visit the village of Eyam in January, it is a beautiful village nestling in the hills of Derbyshire. The story is that of the song. The Eyam link provided by Noreen is good, but you cannot beat goning there and seeing it for yourself.
These peoples self sacrifice, locking themselves into the village, letting no-one in and no-one out to prevent the plague spreading has extra significance to me at the moment, during this Foot & Mouth outbreak
Eyam had a wonderful effect on me, it has a peace about it, I left there feeling at peace with the world, and humbled by these peoples actions.
I bought a book there called Eyam Plague 1665 - 1666 by John Clifford, it is a little paperback pamphlet, You can contact him at the following addres:
John Clifford, Eyam, Derbyshire
Hope this helps!
Lucy