The real challenge to the Webmaster is to set up your Web site so that your site shows up as close to the top of the list as possible. This is the main thrust of this tirade. Talk to the Engines Submitting your URL to a search engine is fairly straightforward. Some make you look around a bit more. You'll then fill out a form of some kind, some require nothing more than your URL, and others require pages of information.
Spiders are just a cutesy name for a specialized program that compiles index information.
The spider looks at your site, catalogues the text it finds there, and adds it to the search engine's master index. Once your site is indexed, people using the search engine can find you. Once you've submitted your site, you usually don't have to do it again. Most search engines send the spiders out on some schedule to sites they know about so that their indexes stay more or less up to date. It's a good idea to check back every few months to see where your site falls in the list and resubmit if necessary.