But remember, even if you spend money on a search engine position, you still need a nice accurate description. People won't click unless they know where they're clicking to. As for the rest of the search engines, you're an idiot if you don't submit to them. The question is how. Well, that depends on the engine.
Engines register sites in different ways.
One way is to register to a bunch of them with either a piece of software, or a web service. Some sites such as Yahoo require you to manually submit your site.