As far I know it was about Meta tags back in the days, but right now you dont even have to do that (anyone correct me if Im wrong). What I heard is that the "crawlers" (google,yahoo search bots) will detect your page as number of visits and then arrange it in the search engine results by # of visits sorting them decreasingly. (The few visited last on results). What you can do to get as more visits as needed is to install "Search Engine Optimization" on your website like "sillyboy" posted. You can find more info here: http://www.livingroom.org.au/searchengineoptimization/ and all over the world WIIIIIIDE web :P
google for google webmaster tools
get a webmaster account
read the webmaster helpscreens
optimize your design according to the rules posted
submit your site for indexing
dont use any SEO sites till after you read the google info,
there are some link exchanges that get you delisted
You really do not have to do anything, except make sure the site is searchable by robots.
Your content itself determines whether or not a search engine will find it.
But beware. The searchable content must be in the plain text of the html files. The search engine can't see content in images or movies, content added by scripts, content in server-side files, or any other content. It can see the alt text for img tags.