The Art of Unix Programming, by Eric S. Raymond

There are hundreds of thousands of distilled man-years of programming
wisdom in this book. Some of it was already familiar to me from hard-won
experience; some of it was new to me; some of it made me see aspects of
my current project in a new light. It’s the sort of book that puts words
to things I know perfectly well but have never verbalized.

If you’re a programmer, get a copy of this; it’s a fun read, and I
guarantee you’ll learn something you didn’t know before.