A web directory is not a search engine and does not display lists of web pages based on keywords; instead, it lists web sites by category and subcategory. The categorization is usually based on the whole web site rather than one page or a set of keywords, and sites are often limited to inclusion in only a few categories. Web directories often allow site owners to directly submit their site for inclusion, and have editors review submissions for fitness.
It will categorize you to sites that are of the same or related topics which can also help you to rate better in google in terms of page rank. There are a lot of web directories, I tried a few. I don't know if it worked but its worth a try than do nothing, right? Most web directory sites are easy to navigate, it just takes a few steps to register. There is a form that you should complete that ask simple questions like, url or your site, site name, user name, password, categories among others. There are sites that also ask for picture or even site description, most of the fields are optional, but the more information you give the more chance of directing more traffic to your site.