3 to five sets with 4 to 12 reps.
Start on the high side and work it down to where on the last couple of sets you're doing less than 8.
or you could just to 5x5, works great esp. for explosive movements.
Just for the record just 'cos it's a push press doesn't make it any different in the rep/set figures.
You could just substitute push press for military press with everythign else the same, I think that's what Mike meant.