Yes. Go to <yoursite>.engin.umich.edu/category/<yourcategory> to view the archive of the chosen category, or <yoursite>.engin.umich.edu/tag/<yourtag> to view the archive of the chosen tag.
The Posts >> Categories page in your dashboard displays all your categories and shows the name, description, and number of posts belonging to each category. If you move your mouse over a category a set of options will appear, allowing you to edit, quick-edit, or delete that category:
If you click Quick Edit, the category will change into an edit box and you can rename the category quickly:
If you click Edit, you will be taken to a separate page where you can edit the name, parent, and description. This functions exactly the same as adding a category.
Clicking on Delete will delete that category. When a category is deleted, all posts that were only in that category will be assigned to the default category. If a post was also in other categories it will remain untouched.