I spent all of my childhood holidays in Norfok!
We always stayed at the pinewoods site at Wells next the sea. It is a little fishing port with one main shopping street and a quay. The caravan site is a nice walk along the sea to the town. The beach is near the caravan site. There is also a little train that you can take to the town from the caravan site and vice versa.
On the site there is a boating lake where you can hire canoes and there is also trampolines and crazy golf. There is also a little shop / cafe.
In the town there are a couple of arcades, an indoor kid play area and a couple of pubs although i don't think the kids rooms in the pubs are very good. The pubs are (just in case you want to google them) : The golden fleece, the ark royal (both on the quay) and the edinburgh, at the top of the main shopping street. There are some cafe's and takeaways and I personally think that "plattens" is the best fish and chips!!

. theyy also have an upstairs resaurant. There is an area at the top of the town called the Butlands which I think has more pubs.
Cromer and Sheringham are large seaside towns although the beaches here aren't as nice as at Wells. They do have a larger selection of shops and Sheringham used to have a large indoor swimming pool (has been so many years since i went there not sure if its still there).
hunstanton is another large seaside town in a similar vein to cromer and sheringham. It used to have a sealife centre, but again not sure if it still does.
Hope this all helps!
Claire