There are two major types of search engine optimization, white hat search engine optimization (the 'good' kind of SEO), and black hat (the 'not so good' kind). There are of course differing opinions about the nature of each type of SEO. Get the information you need to be able to tell them apart and make an informed decision.
There are a number of SEO services which can help contribute to the improvement of the organic search engine rankings of a website. These services include, but are not limited to, on-page (or on-site) optimization, link building, search engine friendly website design and development, and search engine friendly content writing services.