To learn usability testing you'll probably want to jump straight to "Rocket Surgery Made Easy", by the same author of "Don't make me think" Steve Krug is a for

To learn usability testing you'll probably want to jump straight to "Rocket Surgery Made Easy", by the same author of "Don't make me think" Steve Krug is a former colleague and brilliant guy, but at this stage learning how to test and hear from your users in practice is time 10x better spent than just learning the theory.