For an interesting, if not controversial take on the ‘Black Death’ and the early 14th Century in general, may I recommend;
Baillie M, 2006 New Light on the Black Death: The Cosmic Connection. Tempus, Gloucestershire. (Amazon)
Baillie is perhaps best known for his work within the field of dendrochronology, and so it is interesting to read how he sees the catastrophes incurred during the 1st half of the 14th Century played out in the tree-ring evidence. I believe Baillie puts forward a very strong case for us to re look at what we know about the Black Death in the light of new scientific evidence.