Print all the pages in the same level in a book I am have a book like this

About Us


  --Overview
  --Vision
  --Mission


I want there to be menu like this in the left side when the user is in any of there page.


  --Overview
  --Vision
  --Mission   


Now the links are visible when in About Us page, thats the main parent page. I have spend 2 hours already in google and drupal documentation but no use.
This should work out of the box if you add the book navigation block to a region.

EDIT:

Sorry, I didn't realise that I was on on of the book pages so the book block expands in this case but not on non book pages. The way around this is to use Menu Block and create a menu block that starts at your About Us. Make sure you go into the advanced options of the menu block and select Expand all children of this tree.