Apple imac notebook.

I am tasked with connecting an Apple notebook
I think its a G3. Its definitely a new machine. To a digital projector, for a sales
presentation.The information I have is very
sketchy. I was told that as long as the projector had a Usb or a serial port, it
would work. well guess what? blank screen.
If I get a PIII with quick time, I can get the presentation to work. I don’t have ANY
experience with Apples, can someone help.
I’m sure its a protocol problem or adapter
or something simple like that. Do I have to
go and buy a digital projector specially for
Apples. This is kind of urgent. HELP!!!