Someone already mentioned it but bring water.  For cooking and drinking.  The well water up there can be rough.  

I've never had any issues all over the outer banks beaches with my Jeep or Pathfinder and I rarely reduce my air pressure.  

Should be very quiet in May but last July there was a lot of traffic on the beach in the 4x4 area.  I commented to my wife that the kids had to look both ways on their way to the water especially with the way some folks drive.

I love the outer banks though.  In spite of the increased popularity over the last 20 years or so.

Thanks for all the great replies guys!  got at 12vlt tire inflater last week, specifically for this trip.  also bought a cheapo walmart folding E-tool, which my 5 year old broke with 15 minutes of playing in the mud.
 

Bottled drinking water. Can't say that enough...
Pier fishing.
Rent a jet ski on the sound.
The light house above Corolla.
Watch out for the stupid, wild horses while driving.(Only time I ever saw the things was at night, barely missed one of 'em)
Stay away from the unexploded ordnance.(Actually had the nephews searching for the stuff in a restricted area)
Port O' Call resturant.
Go fly a kite.