Contact your District Executive at Council and ask him/her for the Spanish/English books for Tigers, Cubs, Webelos, New Leaders, and How To Books. The rank books will give your parents the ability to follow along with their sons requirements and help them advance. And the How to Books give them the opportunity to lead a project with the den or pack.
They may or may not be FREE at your site but if they are ask for a few extras to keep for future use. It's great a resource to have around so that everyone can be involved!