Categories and tags help organize blog posts. In many course instances, categories may be used to signal topics or themes that are present in a post and important to the course, while tags work well as keywords that group posts together.
Only Admin and Editor roles may create new categories.
To assign an existing category or create a new category in the categories panel to the right of the “Edit Post”, click on “Add New Category” and complete the field provided. Then, click “Add.” To assign one or more previously created categories to a post, check the box next to the category listed.
Admin, Editor, Author, and Contributors may all select from categories created as well as create new tags.
To add a tag in the "Edit Post" page, type the keyword into the field provided under “Post Tags.” You may also choose from frequently used tags
For more information, please reference the following capability by role chart here: http://codex.wordpress.org/Roles_and_Capabilities#Capability_vs._Role_Table
You may also want to review faculty examples to see how others have used categories and tags to organize class work: https://edblogs.columbia.edu/facultyedblogs-examples/