Using keywords in your blog posts is one way to make sure that your audience sees your posts. I know there is a lot of confusion about keywords (and many people who will charge you a lot of money to find them for you).
Quite simply, keywords are just the words that people type into Google or their search engine of choice to find you. One of the best ways to find keywords (besides using the google keyword tool) is to join forums and facebook groups with your ideal clients — take note of the words they use to describe their problems. Those are likely to be excellent keywords for you.