Many business models are applicable to this portal.
Free for All:
Allow users to create their own pages, allowing them to upload their contact info, web + social media links, description, photos and videos.
This will encourage more businesses to join your portal, which in turn will increase traffic you generate organically from the search engines.
The benefit to this strategy is that your side banner advertisement space becomes more valuable, due to the large number of listings and traffic you posses.
Selling pages for yearly fees to businesses will provides you with more flexibility in terms of how you would like to generate revenue.
You can simply sell a client access to his page for a fixed yearly fee, allowing them to customize their page to their suiting.
An alternative strategy would be to create these pages for free for all businesses, with reduced privileges. This may include a limit on the number of photos, how much contact info is available, and any form of customization.
The second strategy will ensure that your portal is rich enough in content to appear on search engines, generating traffic and demand for your pages. This will encourage businesses to claim their business for a fee in order to further customize their presence and benefit from the already existing traffic to their page.
You can also sell the banner advertisement space for a higher fee than the pages.