Directory tree, adding pages in a new folder

[CK]

Hi, is there a way to look at your entire web server structure (kind of like windows explorer).  Also, how do you create files in new folders?  I'm still messing around with the sample site, and when I create a new content page it doesn't specify where it will be saved.  Where are these new pages saved to?

Also, the menu automatically builds out (from the module PHPLayers?).  Is there an easy way to know what factors build out that menu?  Or an easy way to modify parameters in the interface?  Or do I have to go into the raw php files?

Thanks