SEO is of course search engine optimization and search engine optimization is the process of optimizing, or making your site good for, natural search engine rankings. I use the term natural search engine rankings to simply differentiate SEO from the purchased, or sponsored search engine rankings. So what is important in search engine optimization? There are two primary ideas of search engine optimization – that of on-page seo and that of off-page seo.

As a marketing strategy for increasing a site's relevance, SEO considers how search algorithms work and what people search for. SEO efforts may involve a site's coding, presentation, and structure, as well as fixing problems that could prevent search engine indexing programs from fully spidering a site. Other, important noticeable efforts which include adding perfect content to a site, ensuring that content is easily indexed by search engine robots, and making the site more appealing to users. Another class of techniques, known as black hat SEO or spamdexing, use methods such as link farms and keyword stuffing that tend to harm search engine user experience. Search engines look for sites that employ these techniques and may remove them from their indexes.

The initialism "SEO" can also refer to "search engine optimizers", a term adopted by an industry of consultants who carry out optimization projects on behalf of clients, and by employees who perform SEO services in-house. Search engine optimizers may offer SEO as a stand-alone service or as a part of a broader marketing campaign. Because effective SEO may require changes to the HTML source code of a site, SEO tactics may be incorporated into web site development and design. The term "search engine friendly" may be used to describe web site designs, menus, content management systems and shopping carts that are easy to optimize.
Now, I guess you have a website or developing one and you want to get it to the top search engine rankings. Well, If you have money I suggest you pay to an experienced SEO consultant working for one of the top SEO companies.
Yet, if you do not have money, you can try doing it alone. But, be warned – a good SEO solution is time consuming. No matter which SEO software or SEO service you will be using, it will take you at least a couple of months to get your website to top search engines ranking.
Your first step would have to be reading more about the subject – reading about meta tags optimization services, keyword services, back links methods and organic SEO and using free SEO services like SEO toolbars and online SEO software. Good luck.