Whilst not a comprehensive bibliography, here are some ‘must reads’.
The British Railways Handbook for Steam Railway Locomotive Enginemen
Sometimes known as ‘the black book’, this has long been out of print, but by chance I found a PDF copy online and have uploaded it here for use as a reference tool. Click the links below to download the sections.
Christian Wolmar
I’ve heavily referenced Christian’s books in many episodes. I can heartily recommend his works on railway history and the effect of trains on the world.
Fire and Steam: How the Railways Transformed Britain
Blood, Iron and Gold: How the Railways Transformed the World