Agile Smells: Iteration Zero
I've never been a fan of Iteration Zero as a thing. (The only thing worse, in my opinion, is Iteration H, where H stands for "hardening!"). Teams should be able to start work right away, and the need for an Iteration Zero is a smell--something about the organization delays the team in being ready to start work. Not cool, organization!
Johanna Rothman has a fantastic article on Iteration Zero posted on Gantthead that I think does an excellent job explaining how a proper (less smell-y) Iteration Zero should be used.