I'm hosting and managing a WordPress-based lesson swap site for my classmates in an Elementary Education program. Posts contain lesson plans and categories are based on grade and subject.
Some of them are moderately technologically inept, so I don't want to tell them to edit each other's posts--yikes! But, I do want them to be able to at least suggest, if not actually add, categories for each other's posts; for example, a lesson intended for second grade could also work with third. I don't want them to just say so in a comment; it'd look tacky and be hard to keep track of if the site gets busy. My programming skills are crap so I'm looking for a plugin. Does anyone know if this even exists and where to find it?