Big image 
use view slider
you need create node type "slider" from this link
and it's automatically will be show on main page.
also you can off not used images . for this you need go to
use filter form : Show only items where ->type is "slider"
form 1. you can select what do you with marked nodes 
if you don't need show them you can select "unpublish"
or edit from (3)to add changes in exsisting image