Krug, S. (2005). Don't make me think: a common sense approach to web usability. 2nd edition. New Riders Press.
isbn: 0321344758
Morville, P. (2005). Ambient findability: what we find changes who we become. O'Reilly Media, Inc.
isbn: 0596007655 (it has a lemur on the front)
Segaran, T. (2007). Programming collective intelligence: building smart web 2.0 applications. O'Reilly Media, Inc.
isbn: 13:9780596529321 (it has penguins on the front)
