Ranking certain terms or keywords is not the primary option of search engine optimization, rather it is done to help site owners fulfill business objectives of their sites. Indeed, ranking well for a few terms among the many possibilities does not guarantee more sales. This needs a huge work to be done. A successful Internet marketing campaign may drive organic search results to pages using paid advertising like "google adwords or overture", creating backlinks, addressing technical issues that may keep search engines crawling & indexing a website properly.
Search Engine Optimizaition (SEO) and Web Promotion goes hand to hand. Whatever is SE's ranking criteria, proper web pages optimization and strong web site promotion can work a lot to rank you website. Whatever efforts you are putting, but avoid any "black hat techniqe" for ranking. Search engines do not prefer it and will penalize your website for doing that. You can do it yourself but it require a lot of time & effort to learn SEO website promtion concepts. As an alternate you can outsource this task to any seo website promotion firm nearby in your area like www.rockintech.com .?
There are many methods that you can use for web site promotion such as specific search engine submissons, Article submissions, Press release submissions, directory submissions, blogging, social networking and many others. Content writing is a trick when optimizing website. You can do it yourself, if you have sound understanding of SEO or else forward the work to any SEO consultant . If you still want to develop a website, start doing optimization at once since starting so there is less possibiliy of a problem like "Google Sandbox".