Ok first of all i dont know alot about
seo but i learned a little from my
seo who is a master. You need to optimize your metatags first(title, description,keywords). There are a few free ways to get links. One is directories as u allready know.
The other would be to find relevant forums that are closely related to your website and signup and poist there and add your signature link to your posts in the form of a hyperlink with your main keyword as the hyperlink to your website.
This is a great free way to get backlinks for ur site.