The Mythical Man-Month

I ran across a copy of "The Mythical Man-Month" in a second hand book shop yesterday.

Despite being written back in 1975, the book is a still Delphic oracle of software engineering. I credit it (and the friend who introduced me to it) with starting the boost me from a code-monkey-programmer to a software engineer.

The largest theme of the book is that adding manpower to a late software project makes it later.
i.e. if you're behind schedule, adding a newbie is NOT going to help.

Sounds like a truism in these days of XP/Agile/Scrum and so on, but it was revolutionary back then.