In reply to eldre070:
There are some really nice crags near Hameln - the Ith. Lovely outcrops. Kept me happy for my two years in Germany. Near the villages of Holzen, Marienau, Coppenbrugge. It's on the ridge with the airfield on top.
http://www.worldtopo.com/topoboek.php?topo=554
/www.ig-klettern-niedersachsen.de/ith.htm
google 'ith klettern'
If you head the other way, there are some interesting puddingstone crags near Aachen, and a bit further gets you to Freyr, which is great for a weekend. I used to go to Freyr from mid-way between Hannover and Hamburg, so from Paderborn is quite a bit closer