a couple of months ago i started reading a fascinating book: Design Patterns Explained (Shalloway and Trott) and then paused and started reading Agile Java (Langr)(another excelent book!); both refer a lot to agile technics; your link does that too
its curious because while my first referenced book introduces patterns to an initiated public, the second teaches java from the very beginning
then its quite curious to watch both books introduce Strategy Pattern, talk about closing a class to change and so on
If you liked those books, you'll probably love Uncle Bob's "Agile Software Development - Principles, Patterns and Practices"...
The soul is dyed the color of its thoughts. Think only on those things that are in line with your principles and can bear the light of day. The content of your character is your choice. Day by day, what you do is who you become. Your integrity is your destiny - it is the light that guides your way. - Heraclitus