Edaya

A classic.  Gives many examples of unfortunate design choices that reduce usability.

• Stove knobs without intuitive mapping to burners
• Refrigerator / Freezer temperature adjustment

A good introduction to patents.
Also useful when working with a patent attorney.

A very readable book full of simple practical examples.
The author clearly explains how to:

• Choose a test appropriate to your situation
• Choose a test when your sample size is small
• Avoid common errors such as misusing the t-test