I am using Dojo Dgrid however i am trying to add a checkbox column however i am not sure of the approach.
Most of the tutorials i have been looking
If you want to have a column with checkboxes for the purpose of selecting rows, you should set your sights on the selector column plugin rather than editor. selector is specifically designed to render checkboxes (or radio buttons) in each cell that ties in to the Selection mixin when checked.
See the documentation in the wiki, and the selector test page.