Local event marketing to promote your services...

How about being more specific?

Yes. Please describe the event, event location, and event demographics. How you market a local event is going to be dependent on the event's demographics.

Example: An event targeting Post-War Cohorts in Marceline, MO isn't going to draw a lot of attendees from social media. Television advertising an event targeting NYC Millinniums would be a waste of money.

Eventbrite, Brown Paper Tickets, Craigslist and other local sites and blogs.
Flyers and posters where appropriate. Facebook campaigns based on interests in the event - obviously a FB page for the event.

Google display ads in the local area with the event image.

Have an early ticket discount. Start promoting an email list for those that want early tickets. Do this before you start selling tickets.

Are there any organizations in the area that can help you market or provide access to their list?

Depending on the type of event the alternative newspapers and bus/subway station signs can also help.

Press release to all the local papers and contact all the local papers with show info.

Network and pass out postcards to any and everyone you know.

My experience is that you get an initial bump when you start promoting the event and then it slows down. The last three days before the event ticket sales/registrations start to climb reaching a peak the day of/ just before the event.

You want to be hitting your audience from as many sources as possible. The goal is for the marketing to create momentum so that people start telling their friends (Word of Mouth).