Cycling in Norfolk
When it comes to cycling events, Norfolk is in the Eastern region. If you are interested in time trialling, then the East District Cycling Association (EDCA) is the best place to start; you will also want to look at the Cycling Time Trials website for B courses, and at the Eastern Counties Cycling Association (ECCA). For cyclo-cross (between late Aug and early Feb), there's the Eastern Cyclo-cross League.
There are many grass-roots clubs in the county (such as VC Norwich, VC Barrachi, CC Breckland, North Norfolk Wheelers, Iceni Velo), but my personal favourite is Great Yarmouth CC.