you'll find three differnt books (in different editions as well). The first and in my opinion most useful for the scratchbuilder is
Buildings and structures of American railroads. A reference book for railroad managers, superintendents, master mechanics, engineers, architects, and students (1893)
There you'll find illustrated descriptions and dimensions from structures as small as watchmens shanties to as big as terminal passenger stations, all with examples from different roads and designs.
Just be warned: Reading those 546 pages of great stuff will take a lot of time but may as well result in some great models.
The second book I'd like to point you to is
American railway bridges and buildings. Official reports, Association railway superintendents bridges and buildings (1898)
It has even more pages (709 that is) and covers also a wide range of railroad related aspects. To me it seems to cover some more technical aspects like strength of ties and timbers and the like. I think it is a good view on prototype practice.
The third book of Walter Gilman Berg is
American Railway Shop Systems (1904)
which honestly I still haven't read. But I think from looking at a few pages it should help those who are modeling a bigger shop area or build an engine shed with full interior.