How does google decide on weather to give your website search results a sub link menu underneath. Such as the one mysql.com gets in the google results. I know you have to have a google site map, but what else?
You do not need a Site Map. To get "Sitelinks": You must rank first. Google must trust your site. Sitelinks are normally only donated when the search query indicates the searcher is looking for a specific website. For example when someone types "WalMart" there's really only one website the user is looking for and so to make the searcher's life easier Google inserts some sitelinks for quicker navigation.