Thats because Your site is isolated ! If you live alone at home with your door closed people wont get dreams of you being in there rite? Unless they see you out or they hear about you from some one. Same is true with google
Even if you submit it to search engines you wont see your site there. For your site to be indexed automatically your site should be visible on net i.e. your site link/address/url should be present on somebody elses website. So when google indexes pages/updates details of that website it checks all the links in there. If your link is present there it will add it to its database and your site will be visible in search engine. So first add your website to social bookmarking sites and communities like
http://mybloglog.com http://blogcatalog.com etc to give exposure to your site.