how to do a roll over menu bar

How do you create a roll over menu bar? Basically so when someone rolls their mouse over linked text or an image a menu bar shows up on the right of the link with linked pages within it. Also how do you create it so that when you roll over the linked text/image a box comes up to the right, larger than the linked text/image, describing what is contained in that link? For example, the links 'APS legislative framework, etc' on this site http://www.apsc.gov.au/index.html. Any help will be appreciated. Thankyou  Read More