No book on Information Architecture and User Interface? Human psychology of decision making? This is not the hard way.
Hard way is to study human behavior and then study how good things were designed around them. Study the thought process behind and try and solve some design problems yourself.
I also read "Don't Make Me Think", but I haven't included it (in this article) because I don't consider it a good book. It felt like some examples were just wrong and I also couldn't take away much value from it, although I may have been biased by my opinions on the matter. Its other flaw is that it bored me after the first third or so.
Also, "The Design of Everyday Things" (included) does talk about the psychology behind user actions. It's pretty good.
Hard way is to study human behavior and then study how good things were designed around them. Study the thought process behind and try and solve some design problems yourself.
This is not the hard way.