1. Do a relative-size estimate the top n stories in the backlog. (Where n is
some number slightly larger than the number of stories that usually fit
in an iteration.)
2. Pick the stories to complete in the iteration.
That's it.I often see teams:
* doing one-by-one story estimation, and debating over how many points to assign.
(The statistical method completely fails when it's done this way.)
* getting into long discussions over the spec. (That's between the dev
and product owner, to be figured out during the iteration.)
* worrying too much about accurate estimates
* worrying too much about how much work to take on