Most consumer cameras have three ways to be on. Camera mode, still picture capture mode, and VTR mode for playback of tape or stills.
Camera on and in VTR mode, hooked to firewire BEFORE you open FCP.
That sequence is important. Otherwise . . . no "settings" on the camera to mess with.
The settings in capture mode in FCP are explained in the manual fairly well. For simplicity . . . when coming in from a DV camera, the FCP capture preset for firewire with 48 k audio at super white levels at 29.9xx frames per second is what you want.
Hope this clears thig up some.
Ian