In a recent post at googlewebmastercentral.blogspot.com , They have explained on how Google discover our links and show it to the Google SERP. They have introduced the Google webmaster tools in addition to their link: operator but what is the difference? They have explained it below.
Unlike the link: operator, this data is much more comprehensive and can be classified, filtered, and downloaded. All you need to do is verify site ownership to see this information.
I have tried to verify the site ownership but the problem in this one is you have to put some meta tag on your header.. I have hard time locating it on the blogger since I an not a programmer. They also divided the links into two types external and internal as described below
What are external links?
External links to your site are the links that reside on pages that do not belong to your domain. For example, if you are viewing links for http://www.google.com/, all the links that do not originate from pages on any subdomain of google.com would appear as external links to your site.What are internal links?
Internal links to your site are the links that reside on pages that belong to your domain. For example, if you are viewing links for http://www.google.com/, all the links that originate from pages on any subdomain of google.com, such as http://www.google.com/ or mobile.google.com, would appear as internal links to your site.
You can also view links to a page on your site,find links to a specific page on your site, Viewing internal links, Downloading links data but till now I am still studying how to do this site mapping I am having hard time to understand the direction of Google. Maybe somebody could help.more here