Search engines use spiders or robots to index Web Sites. After you submit your page to a search engine the spider will visit and index your whole site (in most cases).  Odds are the spiders may not find your site unless you submit it to them.

Each search engine has a submit page you can enter information about your site and the spider will be scheduled to visit your site.  You should only be concerned with those search engines considered to be major players on the World Wide Web.

I focus on these search engines:

Google
Yahoo
MSN

There are also paid search listings and directories, some of these are:

Yahoo Directory - My submission fee is $500 (which includes the first $299 annual Yahoo fee, then $299 each year after that).  Recent surveys list Yahoo Directories as commanding about 23.4% of the search engine traffic.

The Open Directory powers the top listings for AOL and Netscape.  As you may know, The Open Directory is a volunteer project, composed and maintained by volunteer editors who devote their time to building the most comprehensive web directory for the benefit of the search community. 

Their model inherently and necessarily requires subjective judgment in a review process for every site that is listed in the ODP. I cannot 'guarantee' site placement in the Open Directory.

More info on search engines from SearchEngineWatch.com