First hand I can tell you this… don’t use a Mini DV cam (period) go HD if possible. But If you absolutely have to…
Lights ( a good soft but bright source that will evenly illuminate the whole screen) about 1 stop below your key. Keep your talent separated from the screen (distance) as much as you can while still keeping them in the frame with the greenscreen.
Software – After Effects 7.0 or Shake. Sounds like you don’t have much of a budget so these are the programs to use… and find a good composite artist.