Any web page author would be wise to register in these search engines. They constitute a major portion of the traffic. Some search services use categories to organize web pages and will allow you to register in only a finite number of them. Many services only allow you to register under two categories. Explore the site first and find out which category best fits your product or service.
Many search services require a list of keywords, a description, or both.
Choose these carefully and make sure they encompass everything your product or service provides. In a few days their robots come in and browse your site and use your title as the description. It is important to list as many keywords or descriptions of your site as possible on your front page. A word of caution, however. Don't be over zealous by repeating keywords.