In reply to payney1973:
Good luck! My other half lives in Celle, and it's as flat as the proverbial witches'.....
The nearest (and nicest) spot is the Okertal, just outside Goslar - very grit-like, with plenty of trad, some sport, and a load of bouldering, all in a really pretty area next to the river, and a good pub with cheap beer and top food right next to the parking spot. I guess it'll take about 80mins from Hohne. There's also the Ith, which is west of Goslar but I much prefer the Okertal. Thers are guidebooks, but they can take a bit of finding in the shops - try IG Klettern Niedersachsen e.V. and look for
Wolfgang Brandt, Götz Wiechmann: "Wo die Felsnasen schnarchen - Genußklettern an den besten Felsen des Harzes" - KAMIN AlpinVerlag, 1998. ISBN 3-925997-05-9
for the Okertal, and "Klettern im Norden" for the Ith
Arne Grage, Stephen Grage, Ralf Kowalski: "Klettern im Norden - Band 1" (Ith, Selter, Kanstein, Süntel, Wesergebirge, Brunkensen) - Emu-Media, 2004. (Bezug: www.kletternimnorden.de)
Hope that helps, cheers, JW