SEO content writing is something that requires a certain degree of skill. While you don't need to
necessarily hire the next Shakespeare, you will need someone very talented and well-informed to take on this vital part of 21st century promotions. The writer you need to find is someone who can effectively take several different and relevant keywords and phrases for your site, and incorporate them into a blog post or article that's both interesting and informative. Beware of anyone who over-pads their work with your chosen terms, as this is known as "keyword stuffing" -- considered to be an unethical, or "black hat" tactic that will quickly get your site blacklisted from the legitimate web once any such shenanigans are found out.
Now that you are well aware of the bare bones basics, make sure that any halfway decent scribe you consider is aware that there is more to successful content writing than shoehorning relevant keywords into a sentence. When it comes to blogging in general, you should be aware that this is primarily a social media venture. Unlike Facebook or Twitter, which limit the characters, lines, et cetera that you can use, a blog usually allows for far more freedom.
While writing the next "War and Peace" is not the greatest idea for a blog format, the ability to complete a thought and explain concepts adequately to the casual visitor can prove to be invaluable. If a given reader finds a blog post on a given topic to be interesting enough, he or she might share a link to that post on their social media accounts for their friends and followers to read. The more people share your blog posts on social media sites, the more of a boost your site will get not only in traffic/pageviews, but also in keyword association/page rank for these terms.
Besides the ability to light a spark in the imaginations of your readers, your professional SEO content writing guru should also be able to optimize a given piece for specific keywords. For example, words and phrases that are marked in header tags are going to offer a stronger association/page ranking than those in your normal web copy. Your content writer should be able to write a catchy and keyword-rich title, break up the post into simple concepts that are easy to understand, and should know how to create effective headings and sub-headings 
whenever different concepts are introduced in order to pack a maximum punch.
Besides finding an engaging content writing professional who knows these SEO basics, you should also look for someone who has at least a decent familiarity with your field. This will allow your content writer of choice to converse fairly fluently on the topics at hand, thus increasing the value of your business blog writing to the average reader overall. Make sure that your content writer of choice is also diligent about checking the reach of their work to others on a regular basis via your page metrics, as well. A good writer should know when to adjust their approach in order to pull a few more eyeballs toward your site!
