Nicks pretty much covered it.
I would Throw in West Runton to Sheringham for rocks, cliffs, groynes galore and very worn sea defences.
Morston for a few boats and more Marshes, Cley for a shingle beach that goes for miles a few boats a couple of nice galleries and a windmill.
Blakeney already been mentioned, nice long walk to the beach at Cley through the Marshes.
Then Wells for the beach huts and Holkham for the Dunes asNick mentioned, huge expanse of sand, dunes and the Pine forest is worth a walk through too.
Heading East Of Cromer, Happisburgh light house worth a look.
Hope you have a great holiday and if you want to meet up just Pm me.