Redmine

I have installed scrum plugin, issue_grouping and story decomposition. I have follwoing queries regarding scrum implementation using redmine.

Can you tell me that

1. How to define the sprint start and end date there is no option.
   2. How to decompose the story into different tasks. if there is no UI elements.? There is no such thing on the Spring backlog neither indication of an option like "Create a Sprint" for which we set a start and finish date along with dragging some stories from the product backlog to be implemented.
   3. How velocity charts will be created ?
   4. Scrum plugin just changed the old issue into product backlog and new issue into sprint backlog. isn't?

Redmine detail

vesion 0.8.2
ruby 1.8.7
mattetti-googlecharts (1.3.6) rails (2.2.2) rake (0.8.4, 0.8.3) rubygems-update (1.3.1)

can anyone post the screen shoot for product backlog and sprint backlog which is fully implemented.