Ok, well..depending on where you are there are different ways to go.
If you're coming from the Belt Parkway, heading eastbound:
Take the Sunrise Highway exit (I think Exit 21B) just before the Belt ends and splits into the Cross Island and the Southern State.
Follow Sunrise Hwy for a while. You will see a split where Sunrise goes left and Merrick Rd goes right. Follow Merrick Rd to the right.
Right after that split, you will see Lincoln Ave. You want to make a right on Lincoln.
That eventually merges into Long Beach Rd. You will take a right turn on Long Beach road.
Stay to your left. The Nathans will come up on the left after about a mile or so. It's in the parking lot.
If you're coming down the Cross Island southbound it's a little different, I am not too confident of this because I have never done this, but I believe this would be the route to take:
Take the Cross Island all the way to the end and get on the Belt Pkwy westbound.
Take exit 24B (I believe) which is Merrick Rd. Make a left onto side street at light at end of ramp, then make a right at the next light onto Merrick Rd.
Follow this road for quite a ways. Eventually you will see Lincoln Ave coming up on your right.
You want to make a right on Lincoln.
That eventually merges into Long Beach Rd. You will take a right turn on Long Beach road.
Stay to your left. The Nathans will come up on the left after about a mile or so. It's in the parking lot.
.
I copied these directions as someone gave them to me. They work quite well and you shouldn't have a problem. The one problem getting onto merrick road I've corrected.