If you have a new website and want to build traffic it's a very good idea to submit it to the search engines so they can visit it, index its content and include it in their search results.

While there are many search engines, most of them account for a very small part of the searches conducted online. The big three in Australia are Google, Yahoo and Bing which together accounting for virtually all searches.

Google: http://www.google.com.au/addurl/
Yahoo!: http://siteexplorer.search.yahoo.com/au/free/submit
Bing:    http://www.bing.com/docs/submit.aspx

You may also want to consider Amazon's search engine Alexa, http://www.alexa.com/help/webmasters as well as the Open Directory Project which powers most of the big directories around the web: http://web.dmoz.aol.com/add.html