How to create/modify links to sharepoint quick launch menu?

Adding Links to Quick Launch
http://msdn.microsoft.com/en-us/library/ms427791.aspx

Modifying the quick launch on FeatureActivated
http://social.technet.microsoft.com/Forums/fi/sharepoint2010programming/thread/3998c93e-58d5-44bc-a37f-a83cc3b46347

[Sharepoint] Hide QuickLauch on feature activation
http://crodrigues.com/sharepoint-hide-quicklauch-on-feature-activation/