While there are plenty of books out there on Hammer Studios, and trust me, I know since I probably have most of them, this multiple volume book series that Peveril Publishing has been putting out is a set that would probably answer many, if not all, of your Hammer question. The first 2 volumes of their series The House that Hammer Built have been released, volume 1 covers the years between 1934 to 1949, while volume 2 covers 1950 to 1954. And they have just released the cover for the 3rd volume, which will cover the years 1955 to 1959, which is when the studio really exploded all over the world with their remake of Dracula in 1957.