I have read Anthony Beevor's The Spanish Civil War and Tremlett's Ghosts of Spain over the past few weeks, and I am about to re-read Orwell's Homage To Catalonia. Beyond that, does anybody have any suggestions with regards to good books about Spanish history, from the middle ages to pretty much the present?

Very specific in its focus, but very readable is Mark Kurlansky's The Basque History of the World: The Story of a Nation . It touches on the greater country, but more as it relates to the Basque country.

A book that is wonderful, as much as a document of a particular moment in Spanish history (viz. 1968) is James Michener's Iberia.

Hope this helps.