Capture as per your shoot settings. ie create a project that matches the settings that you shoot in (eg 24p NTSC)
Export to what ever you need ( eg DVD, Quicktime, wmv etc) although I always export same as per the project ( Lossless DV) first and I call that the MASTER then I produce any other media from that.
In my case I shoot DV 25p PAL so I bring that into a DV 25p PAL Premiere Project. I export as a DV.avi ( therefore lossless through the process). If I wanted a Quicktime movie I would then open the avi in Quicktime Pro and export it from there.