Thoughts:
A "classic" from 1999. Lots of interesting "roots" of some now commonly known programming principles. I was particularly gleeful to hear the lauding of plain text files - my preferred way of storing almost everything. I think even JSON is mentioned alongside the more ubiquitous XML in 1999.
Source control, particularly since git/github, is now defacto. The authors were way ahead of this fact. Similarly they mention something dangerously similar to test driven design, modern buzzwords sure, but still a great way to work. There are also a lot of general how to deal with day-to-day problems programmers face, like customer spec sheets, deadlines, and communication.
Interesting and breezy read, would recommend as light reading to any programmer.