The search results will serve up listings from different categories. Go to those categories and determine which one is most appropriate for your site. Be sure to review the subcategory descriptions, whenever possible, to determine if your site is appropriate to that category or subcategory. Multiple submissions, especially to inappropriate categories, will not be tolerated. Property rentals, design, contracting, construction and home builders are also located in Business .
World is for sites in languages other than English.
Each has categories of its own. Shopping is for retail and online sales sites. Regional contains many business listings for specific localities. If your organization serves a small geographic area, Regional may be the best location for your listing. My site used to be listed in the Open Directory, but I can't find it now.