Well first you have to get your site indexed in the search engine. This can be done by submitting your URL to the search engine. The bot from the search engine will then crawl to your site and index your site.

Here are some of the links where you can add your URL:
Google: http://www.google.com/addurl/
Yahoo: http://submit.search.yahoo.com/free/request
MSN: http://submitit.bcentral.com/msnsubmit.htm

Hope this helps a bit.

-Allabout42

Search engine optimization is the key.

Costly depending on keywords/competition that your is targeting.