Develop a good sense of who these type of users are... you might find that they congregate on Twitter - therefore you should focus on building a good following there.
Maybe your demographic doesn't use social media in which case you have find them in person and find the common places of where online do they go to when 'online' and or what do they subscribe to.

Local listings are also a big help when wanting to leverage google searches in your area, obviously good SEO.

Facebook groups could be a good place just as meetup could be... but depending on your target market.