Stupid n00b question: BootLoader

[usib]

I am obviously stupid, but I can't find the place on the Wiki or otherwise where it would explain how to use the BootLoader. When I press the three things, I get the screen saying "BootLoader" at the top and "Serial" or "USB" at the bottom (depending on whether the USB cable is connected), and then it just sits there. What is supposed to happen next?
(I have played with the iPAQ H3600 quite a bit, there it was different: you had to have a serial cradle to connect to the PC's serial port, and then use something like kermit or minicom to flash and boot it. Is it a similar deal here? like a usb comport and a bootloader command language?)