It depends on how many of you are going and how much time you have. For a large group, if you can make it a longer weekend, the cheapest way is to drive. It takes about 12 hours each way and you take the ferry from Harwich to the Hook of Holland.

If you don't have time to drive, you can start by finding a cheap flight from Norwich to Berlin and then choose the area of Berllin you want to stay in (eg Schoeneberg), put that in a search engine and add 'weekend breaks hotels'. This should lead you to plenty of choice. Or you could go for a weekend package - this is the easiest way, but may involve travelling via a London airport, as there don't seem to be a lot of cheap weekend deals direct from Norwich to Berlin at the moment. (Ask your travel agent, though - they can find the best bargains.)