Here are some sites about Nightingale, who has, as it happens, a connection with Sheffield. And many other places, including Leeds, where the magnificent Leeds General Infirmary, designed by George Gilbert Scott, is modelled on her designs for a hospital, and Leicester, where the Odames Ward, the site of the newly opened library at the Leicester Royal Infirmary, is a "Nightingale Ward".
The Florence Nightingale Museum in London has a biography of her. Their digitisation programme, in association with Boston University, has digitised many of her letters.
The MacTutor History of Mathematics site at St Andrews University, Scotland, has a page about her, because of her work with statistics.
One of the things I am reading on the train at the moment is Mark Bostridge's biography of her, published by Viking in 2008 and Penguin in 2009.
And the connection with Sheffield? Florence's father William, who was born Shore but changed his name to Nightingale when he came into a family inheritance, lived as a boy at Tapton Hall, in Shore Lane, Fulwood. It is still there, now a wedding and dining location. I don't yet know if Shore Lane was called that then, or whether it has been so called since.