"when I put it on cpu to edit in FCP it is dark" -
Be very carefull as to how you judge the darkness and lightness of your video when editing. First of all, your computer screen cannot be used as a guide, and secondly if you have a video NTSC monitor plugged into your DV camcorder and have the camcorder plugged into Firewire to monitor FCP, then the video you see on the external NTSC monitor will look darker than it really is. My article at
http://www.signvideo.com/dv-black-levels-dvd-authoring-mpeg-2-part-1.htm will explain why that is and what you can do about it, but basically your DV camcorder does not provide the legal NTSC analog signal. If you just try to adjust things in FCP to make the video look lighter then you will end up producing DVD's that may be way too light.