As a small business finding time to do your SEO internally is one of the biggest barriers you will come across, unfortunately to do it well you need to work at it, this means setting aside time each day, either that or outsourcing it.
SEO is partly about trial and error, once you have it setup rather than just leaving it you need to maintain it and as a lantern will go out if you don’t keep turning the wick your SEO rankings will drop and die out if you don’t keep adding fresh content to your site.
Content creation has always been the best way to achieve good rankings, there have been other flashes in the pan in the past but Google want to see you creating high quality unique content on a regular basis for your website and you can then slip in a few keywords carefully to make sure you rank for the right terms.
To research those keywords terms you may want to use an SEO company, if you do them yourself you should use professional software rather than simply Google’s keyword tool that over-simplifies choosing keywords; the level of competition plus the quality of competition (not considered by Google’s tool) is vital and you should choose your battles carefully.