If you are curious about how to run a web directory, there are plenty of directory scripts available and certainly wordpress is worth considering. All you have to do is install a wordpress theme or a plugin to convert your wordpress blog to a powerful link directory.
These are the wordpress themes you need to install to your own web directory for wordpress and need to customize accordingly.
Directory Press Theme
Website – http://directorypress.net
WordPress Article Directory
Website: http://www.templatic.com
WordPress Classifieds Directory
Website – http://classifiedstheme.com
WordPress Directory Plugins
These are the wordpress plugins you will need to install to convert your wordpress installation to directory structure.
WordPress Link Directory
http://wordpress.org/extend/plugins/wordpress-link-directory/
