Typically, you can transfer the data on the miniDV via the camcorder that uses the miniDV being connected yo your computer i.e. the miniDV will be in your camcorder which itself is connected to your PC (USB, Firewire, etc.).
Often times, the camcorder comes with software that will transfer and either convert the video into computer readable format (e.g. mpeg) that can then be burnt to DVD (using software like Premiere, Final Cut, Windows DVDMaker, etc.), or include DVD burning features itself.
There are other ways (such as connecting the camcorder directly to a DVD recorder, commercial disc replicator, etc.) but via the (ubiquitous) PC is probably the most accessible for the average person.