97 Things Every Programmer Should Know is a collection of short essays on many programming topics – coding, testing, pair programming, and more.
You can get a full list of the essays, as well as the full content. It was a bit surprising how much shorter and less readable they seem in this format, compared to the MOBI file.
The essays are somewhat useful, but most of them cover subjects that any good programmer should already have seen elsewhere, and thus were not very useful to me.
That said, while the amount of notes that I took in this book is way below average, it still contains plenty of interesting content.
Some of the essays I found useful or interesting:
66. Prevent errors (using Undo logging to review error prone section)
76. The Single Responsibility Principle (separating classes for how they change)
Overall I'd say that the book is worth the money and time – but just barely.