How can i advertise my fathers small Concrete Curbing and landscaping buisness for free?

I want to advertise my father so he can raise his income and get more clients? I already tried Craigslist and a Webpage. What other things should i do to secure that he gets more successful? Please Help ASAP!

Try BiggestClassifieds.com which comes with other attractive online advertising rates.
The media is well networked with other sites.
You may write to ask for Professional Webmasters Advice.