There are two ways you can go about it. If you have the knowledge, expertise and the time to write high quality articles about your niche then you may very well do so and submit articles for free in the many article directories on  the internet.

On the other hand if you are squeezed for time handling other responsibilities or don’t have the ability to write authoritative content then you can render the services of an SEO writer who can write up some decent content for you. Then you follow the same procedure and submit free articles to the online directories.

In order to get the maximum link juice out of your articles you should publish them on article directories that have a good repo with major search engines. Articlealley.com for one is a great example of such sites. Article directories as such are actively searched by thousands of users across the globe.

This means once you place your articles in these directories you will have started a round the clock advertising campaign without you having to man it. Every time someone makes a search for your keyword topics your article will pop up and if it manages to impress the reader he can follow your link to  your website.