Check out the Administration Menus section in the Codex, I actually used it pretty heavily over the last couple days to create a sub-menu and it helped a lot. It goes into detail on the top level menus as well.
You’ll specifically need the add_menu_page() function to create the top level menu, as well as the add_submenu_page() function to create the sub menus. From there it’s just a matter of meticulously adding options and setting fields.
Also of great help in understanding the flow of things was Otto’s WordPress Settings API Tutorial.