Your site will be on all search engines. What you mean is you want a higher ranking so people don't have to look at 100s of sites before they find yours. There are basically three things that determine this ranking.
1. As drip said, keywords are important. Keywords are what determine how a search engine will classify your site IE. art, science, writing, etc. As an example, porn sites will put in hundreds of key words unrelated to any actual contents on the site so that any search may turn up the site as one of the results.
2. Links. search engines use sprite software called spiders that roam the net looking for sites to list. One of the things they focus on is how many other sites link to yours. The more sites that have links to yours on their sites, the higher the ranking.
3. While it may seem obvious, the more hits your site gets, the higher in the rankings it will be.
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