Don't Make Me Think!: A Common Sense Approach to Web Usability by Steve Krug, Que 2000
Don't Make Me Think! is a humorous and to-the-point guide to web usability. Creating sites that truly meet the needs and expectations of the wide range of online users is not easy, but Krug introduces techniques that make it as straightforward as possible.
The title refers to Krug's main aim, which is to introduce you to methods that will make it easy for people to surf round your web site without having to think very hard.