If you're unsure on how to Optimize your website for local results then it would be best to hire an SEO company that can do the required things needed to rank local for you.
It's very hard to explain completely in detail here but what you can do to rank a Directory Website or any other website in the Local Results is to Optimize your Meta Description and Title Tags to include the keywords for your local area.
So if you're wanting to Rank your website local for New York City then you'd put New York City in the Title and Meta Description.
And you'd also put New York in the content on the website or in blog posts to rank for local search results.
You should also claim and optimize your website for Google My Business as well and use local structured markup too.