So, this is probably fairly easy. But it's been a while since I've been anywhere else than Visual Studio. I want to hide e.g. Tasks, Calendar and Site Pages in the "Quick Launch". Where do i find the option for doing this?
Here is article with everything about quick launch menu and items inside: http://www.endusersharepoint.com/EUSP2010/2010/06/04/navigating-sharepoint-2010-part-2-the-quick-launch/ (...maybe with more information then you need). Do you have enabled Publishing features on your site?