Directory idea with a social media twist

I am thinking about starting an online directory for my local area real estate agents. I need the site to be easily navigated by users, and make it to where real estate agents can post there info and a few images of there homes or what have you. I would like to have some advertising spots, or charge some kind of "premium" fee. Any ideas on the best way to do this?? Would using a CMS work well for agents to login and post, update, etc? Thanks!