New to jQuery. I'd like to make a menu like the one in the attached mockup. "parent level two" just shows and hides its child links. if, in theory, there was a "parent level three" it would not close "parent level two" when you expand level 3. only the user clicking expands and collapses the sub menus.

I want to know where I should begin. what do I need to look into?  I really would like to use jquery and be happy and good at it. any amount of help you're willing to offer would be ultra mega appreciated. thanks very much in advance.