After submitting your site to the search engines and getting it indexed, you can start "popularizing" your site by submitting to directories. Word of warning though, this isn't the best way to do things and all of your links should
NOT come from directories. This is just to get things started. Ultimately your website should create enough interest in your target market for people to link to it on their own accord.
It might be helpful to have a look around this forum and other
SEO forums to find some directories that are safe to use.
Good luck!