welcoe to GoY. Do you know which area you are coming to? is it costal, near a broad or more inland?
There are several members who live in Norfolk so perhaps they can help better than I can. My view is it is typical/average for britain. One lady I know of lives there I'll send her a private message to tell her of your question.

My impression is that it's drier than the average for Britain, and can be colder in winter when the wind blows from the east. On still days, or when the wind isn't blowing from that direction it is probably warmer than the Midlands due to proximity to the sea. Soils are pretty fertile.
On the other hand, this is all rumour and I've never lived there.
http://norfolkcoast.co.uk/feature/weather.htm

Otherwise, acquire yourself a book on British Garden Plants and Flowers, such as the Readers Digest Encyclopaedia - some of those will need warmer conditions than perhaps you can provide in Norfolk, but the book will at least tell you that.

Welcome from me too. I think once you have sorted the house out you will only need to walk around the neighbourhood to find out what the locals grow. Asking them for advice might help you get to know people and gardeners being the sharing people that they are you may be able to acquire plants, seeds or cuttings of what takes your fancy. There are lots of garden centres and nurseries open to the public which will sell what grows locally. Invest in a National Trust Membership and visit some of their properties most of which have well stocked and maintained gardens. Happy gardening.