As JSOP and many others say,
Google[
^] is your friend. Visit him often. There are a lot of plugins already built for people to reuse. I found
this[
^] to be useful. However, if you want to create your own look and feel and maybe custom functionalities for your menu, you might want to familiarize yourself with the jQuery UI widgets by looking at their
demo[
^] and try to play with it on your code.