You can read the blog of a scholastic chess teacher here:
http://lizzyknowsall.blogspot.com/
You'll have to wade through the recent posts about being pregnant and making babies however.
Her 6th Grade chess curriculum was a good read:
https://docs.google.com/file/d/0B4cRSlVgLWb6SGN5Rlh0clhQWUU/edit?usp=sharing
You have to keep it very, very simple.
Try simple games and exercises with only 3 or 4 pieces on the board where they have to capture or find what pieces are threaten. Make it slowly, for example one set of exercises for rook captures alone one day. Next day the bishop, and so.
Only when they can handle how all pieces capture and are able to find all the pieces that are threaten by a given piece you can move to the next step.