Thanks a lot for reaching out about the plugin. When you talk about contributing content, are you referring to content that would live on the front-end of your website, or content that would be private to only board members?
Right now there are only two roles in WordPress that can use the board management system. Board members, who don't have permissions to work with the website's content at all outside the board management tool, and administrators, who obviously have access to everything within the WordPress system.
In regards to sharing information privately with the board, the Board Resources section of the plugin is going to be your best bet. That said, if you're looking for a project management tool, it might be worth checking out Asana or Basecamp.
I hope that helps. Let me know if you have any other questions.