If you're interested in more detail about how a VFS (Virtual File System; the bit where it finds the file and then finds the data in the file) works, Chapter 17 (Another Level of Indirection) in Beautiful Code (http://shop.oreilly.com/product/9780596510046.do ) is well worth a read.
It explains how the VFS in FreeBSD works. How disks, partitions, volumes, filesystems, offsets, etc all get orchestrated together so that the Unix "single directory hierarchy" abstraction works as intended even tho' the actual data may be spread around a number of locations (both local and remote).
The concepts and ideas are largely applicable to other Unixes and Unix-like operating systems.
It's also a great example of how elegantly one can express polymorphic code, even in plain C.
I particularly liked Brian Kernighan's description and implementation of a regex matcher, and Travis Oliphant's discourse about multidimensional iterators in NumPy.
Worth a read.
Beautiful Code  is a well-known book that attempts to examine the development of some successful software projects from the perspective of the lead developers, and how they came to design decisions.
Beautiful Architecture  is a similar book focusing on large-scale project design.
Maybe if a user's submission becomes well liked they could be asked to write a more in-depth explanation or article.
Get dozens of book recommendations delivered straight to your inbox every Thursday.