Submenus and Categories

I am new to The Daily Theme, and need a little help. Under the Top Menus, which appear to be category driven, I have established a category of “E-zine.” Under E-zine, I would like drop down menus for “Current Edition,” “Previous Editions,” and “Submit Your News.” I know how to set up submenus for regular menus, but not menus based off categories, such as the top menu of Daily. Is it possible to have a drop down menu from the top menu? Is there a better way to organize and have readers access archived editions of the magazine? Please advise.