Creating effective backlinks are essential to a successful SEO campaign.
A backlink is link from another website coming into your own website. Backlinks contribute to the PageRank (PR) of your website. A backlink must include your main keyword phrase (kp) in the anchor text. This means creating a link with the words of your main kp e.g. Dallas Car Insurance rather than using the web address as a link or even "Click Here" or "Visit Us".
Backlinks only help to boost rankings if they are from high ranking, high quality websites, in other words websites with a high PR. Ranked out of 10 websites with PR 4 and upwards are worthy sites. Websites with lower PRs are good but more backlinks from this type of websites are needed to equal a website with a high PR. You can check PR by downloading the Google Toolbar.
You can post a backlink in business directories, local directories, social networking sites and other blogs.
Here are some directories where you can post your link for free.
Make sure to add your website address and wherever possible with your main kp.
Read about inbound links straight from the horse's mouth (Google).
Read more about What PageRank Means for Your Website.