Here is some info on google from the google website:
We add thousands of new sites to our index each time we crawl the Web, but if you like, you may submit your URL as well. Submission is not necessary and does not guarantee inclusion in our index. Given the large number of sites submitting URLs, it's likely your pages will be found in an automatic crawl before they make it into our index through the URL submission form. We DO NOT add all submitted URLs to our index, and cannot predict when or if they will appear... You can submit your site as often as you like, but multiple submissions will not improve the likelihood of your site being added or accelerate the process. We do not penalize sites for 'over-submitting'. If you choose to submit your site, only the top-level domain is necessary, as the spiders will follow your internal links to all the rest of the pages.
The best way to ensure Google finds your site is for your page to be linked from lots of pages on other sites. Google's robots jump from page to page on the Web via hyperlinks, so the more sites that link to you, the more likely it is that we'll find you quickly.
Ranking system:b
Google's complex, automated methods make human tampering with our results extremely difficult. And though we do run relevant ads above and next to our results, Google does not sell placement within the results themselves (i.e., no one can buy a higher PageRank). A Google search is an easy, honest and objective way to find high-quality websites with information relevant to your search.
Human beings, who are almost unique in having the ability to learn from the experience of others, are also remarkable for their apparent disinclination to do so.
-Douglas Adams (1959-2001)