I'm a big fan of older programming books, and one of the favourites in my collection is Thomas Plum's 'Reliable Data Structures in C' book from way back when (1

I'm a big fan of older programming books, and one of the favourites in my collection is Thomas Plum's 'Reliable Data Structures in C' book from way back when (1985!). While it pre-dates ANSI C and contains a few quirks you wouldn't necessarily want in production code, I found the book to be a lucid and fantastic resource to help explain how data structures work in C, as it gives hands on applications through the building of a working piece of admin software (albeit a slightly outdated one!). If you're aware of how pre-ANSI C differs from C89/99 et.al with regards to function and parameter declaration, it's worth buying a used copy on Amazon just to leaf through - there are copies going for a single cent (plus shipping) at the moment. His first book 'Learning to Program in C' is also great reference to read alongside K & R (which should be mandatory reading for anyone looking to learn C, not necessarily for the code style or examples but to get a handle on the ethos of the language).