One step of the SEO puzzle that many companies don't give enough consideration to is the Targeted Keyword Research : You can make or break an SEO strategy in the very beginning with your keyword targeting.
Most businesses owners think that everyone searches just like they do and as a result, they tend to use industry jargon as search terms. Although these terms should be a part of the strategy, they should not be the only keywords being optimized for.
You need to think about how your prospective clients are searching. What problems do your services or products solve? The goal is to select the keywords that will drive not only traffic, but targeted conversions. Let's face it, millions of monthly visitors to your site is great, but worthless if none of them are resulting in new business. Furthermore, you should select different levels of keywords to optimize for. SEO is very granular.
Each keyword will rank at its own point in time, and there are many factors that play into when each keyword will rank. More competitive keywords will likely take much longer to rank and will be more difficult to maintain rankings. For this reason, you will want to insure that you have a variety of different keywords, with different levels of competition so that you can achieve some success earlier on while working to achieve rankings with your more competitive and aggressive keywords in the long run.
To get started with your keyword discovery try out a free tool like the Google keyword tool. This will help you to be well on your way to learning more about how the masses are searching for your services.