Urgent please: page menu with children and grandchildren

Hi people, sorry for reposting but it is really urgent, if someone can help me I can pay for your time.
What I need is this:
I have in a div header where I am displaying page menu,and
a second div where I have to display (if any) child nenu.
In addiction, I have to display the grandchild menu in a div inside a content page.
If you don’t have time to do it for me, can you send me to some page where it is explained how to do it?
Thanks a lot