Here's the link answering your first question:
http://en.wikipedia.org/wiki/BIOS
You just have to plug a monitor into the vga connector before you power ON the laptop. In the DELL logo splash screen you will see options (messages) that says 'F1 - Setup' or something. Try each of the options if none of them says about going into BIOS settings. AFAIK you do not need to tell the laptop to use the external monitor (at this stage of the boot up process) before Windows starts.