Is there going to be a draw for the last 16 fixtures?
No, I can't remember the format but if you go on UEFA's site you can predict the bracket to see who would play who: http://europredictor.uefa.com/ (sorry I had to link their site...booo).
If England win the group we play 3rd in Group D. (Currently Czech or Turkey)
If they come 2nd we play the winner of Group F. (Currenty Hungary)
If they come 3rd and go through we play the winner of Group C. (Currently Germany).
Thats how my bracket looks anyway, it may depend on which 3rd place teams you send through.