This is a very long and complicated subject however it
isn't advisable for any website owner not to know something about even though they will mostly delegate the task to their web designer.
There are literally hundreds of different search engines each setting different parameters to the algorithms (formulae to asses the relevance of your site to the browsers search enquiry). Google though is undisputedly the most commonly used search engine (Interestingly Yahoo claim to field 25% of UK enquiries).
To optimise a site can involve time, planning and a lot of thought often using specialist software. It is a fact that in many cases it can take more time to optimise a site than actually build it. It is worth bearing in mind that however intangible it may seem good optimisation is a very valuable investment.
Before getting overwhelmed it is worth remembering that local optimisation for businesses that have a limited operating range can be often relatively easy and for companies operating nationally (or even globally) the costs are equitable with the rewards.
To get your website to the first page of a Google enquiry for the right keywords takes time and patience. However a Google Adwords campaign can get you immediate profitable results. Please contact us to discuss your requirements and get a better understanding of the subject.