An excellent and proven way to get backlinks is to write an article about your topic and publish it at article sites.
Most article sites allow you to put one or two links in the article and/or in your author bio box. Depending on the article site, your article may be picked up by other webmasters looking for content and be published on their websites. If you write good content, your articles might be republished at many other sites which can give you a decent amount of backlinks. If if your article doesn’t get picked up at all, you can still get quite a few backlinks just by submitting to several sites.

Here are a few article directories where you can post your articles:
http://www.ezinearticles.com
http://www.goarticles.com
http://www.infobarrel.com/
http://www.webpronews.com
http://site-reference.com
http://www.articledashboard.com
http://www.topica.com/lists/free_articles
http://www.articlesbase.com
http://www.articles.web.com
http://articles.easywordpress.com
http://articles.directorygold.com
http://www.afroarticles.com/article-dashboard/
http://www.articlefriendly.com
http://www.articlewheel.com/
http://www.top-affiliate.com/articles
http://www.articles-hub.com
http://nero.byethost15.com
http://www.submityournewarticle.com
http://www.articlerich.com
http://www.articlecafe.net

Now some article directories require you to write unique content and you may not reuse it on other directories.
Another thing is that logging in to all those sites and submitting your articles manually is time consuming. Lets say you have already written your article (which takes quite some time, too, if you do not outsource it), it will take you about ten minutes per article site.
For a lazy guy like me this meant looking for solutions – and I found some.
There are lots of article writing and submitting software on the internet, in another post you find a review and comparison of three:
Article Software Comparison.
Another good place to post your articles is on other blogs, you can do that as a guest author, if the blog will let you or you can use systems like 1waylinks and Neurolinker to place your articles on other blogs.