As jcp said, first you need to enable shortcuts in the browser. Once they're enabled. 't' brings you to the top of a page, and 'b' brings you directly to the bottom.
Lock the physical kb in number mode by pressing alt + left-shift together.
Lock the virtual kb in number mode by holding the number (123) key until you see a '123' indicator in the top left corner.
Lock caps on the physical kb by pressing alt + right-shift together.
Lock caps on the virtual kb by holding the shift key.
The BlackBerry help has a list of keyboard shortcuts. There's also one
here in the Torch User Guide.