If its around the Peterborough area there are not going to be any big hills, apart from that it depends on the route - head east to the fens and it's pretty flat, head west and it's rolling. I did a 74 mile ride to the west of Peterborough yesterday and clocked up 4,000 ft of climbing. Either way it should be a good ride.
Edit - the 2 posts above beat me off the lights and are more informed !. In the light of the information passed on, typical East Midlands rolling countryside, I rode some of the route and its certainly a roller coaster.