The NH seacoast area has a lot of deer, but not a ton of huntable land. You'll find more huntable land and bigger deer in Northern NH and most of Maine. I hunt in Southern NH near where I live, and also up in Maine where I grew up.
I'd recommend stopping in at the Kittery trading post(
www.kitterytradingpost.com) on Rte 1 in Kittery Maine when you get to the area, I'm sure they'll point you in the right direction.
-Matt