Wordpress does not have a strong directory-type of structure, which is what it seems you would like to build.
Give Joomla + Mosets Tree a look. Mosets Tree builds a very robust directory very simply. Plus you can have ads, pay for premium placement, etc.. It is not free but for the price it will save you hundreds of hours of trying to build something like it.
I don't work for them, I just use it on one of my sites and love it.