Web directories are filled with websites for every subject imaginable. Chances are there is one perfect category at these directories for your own website. If you want to make a steady income from your site, submitting your website to a number of directories can quickly boost your traffic. Directories at Yahoo and the Open Directory Project are excellent directories to start out with. These directories are free to submit your link to and have many categories to accommodate general and niche websites.
Once you have the initial traffic boost you need from these directories, you can start looking for a more SEO friendly web directory that can provide you with a better percentage of targeted traffic. If you have a more business-oriented website, you can choose one of the business directories that only include specific websites that meet their criteria. Having your website included in a smaller but more discerning directory will get your website noticed.
Remember to look for quality directories. Submitting your website to any directory that will accept it will take more effort than it is worth. Weigh the quality of the directory with others available. It's also a good idea to ask friends or family if they have used a specific directory for their website to see if they recommend it. This will make your website visible to the right people.