Google Site Links are the sub link shown for some sites on the search engine results page. There is no way of forcing Google to link to certain pages, because the links are selected by an automated process. There are occassions when you may want to block some pages being shown, Google allows you to do this through Google Webmaster Tools.
Follow this link if you need help setting up websmaster tools.
Once set-up you can block unwanted site links by selecting 'Links' and then 'Site Links', this tool shows you the current site links and allows you to block unwanted ones.
- Webmasters can now provide feedback on SiteLinks, Google Webmaster Central Blog