Search Engine Optimisation is, quite simply, a method used to increase the likelihood of your website ranking high on a search engine. The content on your website needs to include words that are relevant to what your audience may use to find you in the first place.
SEO will always need a sitemap, so make sure your website has one. The sitemap will allow a search engine to index your sites’ content much quicker than if you did not have a sitemap. Apart from the search engines, it is also a useful tool for site visitors, allowing them to work their way through your site.
The title of each your pages will need keywords, these are words that convey the relevance of the page and that sum up what type of content is on that page. Without them, no one will know what that particular page is about, and will therefore be unlikely to visit the page. With this in mind, Keywords need to be concise; in short, you need a limited amount of keywords. Too many keywords almost defeat the purpose of SEO, it reduces the relevance of the page, and the search engine will not rank the page as high.
To get the most out of your SEO, your keywords need to be found in any of the links that are present or posted on your page, search engines tend to give links preferential treatment over text content, so any links that you do have on your site, make sure your keywords are included.
With time, you will or perhaps you already know who your target audience is. It is logical that you provide pages of content that you feel are relevant to that audience.
Unfortunately, results will not happen instantly, SEO is more a long term project for long term results. In order to help with this long term project, you can use any number of free web analytic tools to see how your changes are affecting your page traffic. Preferably you would use these tools from the start of you SEO campaign, so that you have a baseline to compare to in say, 3 or 6 months time.
In the end, a well crafted and successful SEO campaign will mean that your site appears in an organic search to those people who wish to find a site like yours. People who search for what you provide should see you on that hallowed top results page. It also means that you do not have to pay for pay per click campaigns and other paid for methods of search engine advertising. Allowing people to find you should be made easier by running SEO. The more people that find you, the better it is for your site and your company.