I am very much enjoying Susanna Gregory's books not only would I highly recommend them, but they are also recommended by the evil Dr Nebula.
There are two different series, one set is set in restoration London which is excellent as it gives a personal view of a turbulent time. A time full of religious zealots and economic instability.....hhhmmmmmm.
The other is set in Medieval Cambridge, the first book features the black death. Facts and figures do not convey the scope of the devastation. Go into work and look at your co-workers, one person in three died, in some villages everyone died. Hard to think of it.