The Curse of the Carddecks, Tax on your Product Backlog and Tango!
Your portion of certified value adding agile links ;-)
Fibonacci must die!
The curse of the carddecks
http://practicalagility.blogspot.com/2011/06/fibonacci-must-die.html
What's in a story?
How to break-up functionality into stories
http://blog.agilebuddy.com/2010/12/whats-in-a-story-breaking-things-down.html
How to put performance contstraints into a product backlog
Non-functional requirements as a tax
http://blog.mountaingoatsoftware.com/estimating-non-functional-requirements
Dance with the system
Follow! Lead! Anticipate! Experiment! - Tango!
http://www.noop.nl/2011/06/dance-with-the-system.html