I usually stay at the Grand Hotel that time of year. To make booking your room easier, use
http://oceancity411.com/ 
It will take us about 3 hours to get to the Ocean City area (depending on traffic).
Things I would recommend for the trip:

A sweatshirt or light jacket. Even if it is warm, the island can get windy.
Chapstick is a must too because of the salt air.
Don't forget bug repellent of some sort.
Good walking/hiking shoes or boots.
http://www.nps.gov/asis/planyourvisit/brochures.htmAny questions, you can post it here, email me or message me through the forum.