Google will find your site if it thinks that your site has information that users are looking for and is unique. .Submitting in dirs will not help you 100% about getting high ranks on google or other major search engines . It will play a minor role and the major part will be your web sites CONTENT. I have an article that might help you . Check it out
here. Remember all those topics in the article will help you rank better but will not effect as your content will do .