try searching for SEO
you don't really add your site to google, google has s spidering engine and a literal word filter.
in short you are added to google as other people link onto your site, the more good links to your site the higher your page rank, (obviously if there are no external links to your site then the page rank os zero and you don't even show on google).
nex tthere is a literal word filter that will search through words on your page, you can be marked either up or down depending on the amount of times a phrase is used and the context it's used in...
getting a great google page rank is something of a hit and miss affair, especially for small site webmasters.