The carpark is well known (google the GPS co-ords), its S.E about 38kn from the mouth of the bay. Can't miss it, it'll have about 30 boats sitting on it. We dropped three marlin on monday out there. Live baiting is best, pulling skippers if that fails. It's the old story, find the bait and the fish will be there.
You can grab bonnies to use as skip bait on the headlands on the way out. Jig up for livies once you get there.
You could also just head Est towards the shelf, its about 45km to the start of the drop. Two weeks ago we had six marlin up through the spread there.
Best boat ramp is at soldiers point and it tends not to be as busy, but its a 10km run to the mouth from there, so if you can stand the crowds shoal bay is good.
Luck with it!