In reply to Kevdt:
Hi there. Just stumbled over this topic and i think i can provide some help.
One of your best sources will be the rock-info page of the german alpine club:
http://felsinfo.alpenverein.de/
I hope you already know some german or are at least eager to learn.
I'm afraid North-Rhine-Westphalia is not the best state to move to, climbingwise.
Many of the local potential or used-to-be crags are closed down due to "enviromental" reasons, so always check if a crag is not closed down due to birds breeding, etc.
One of the nearer opportunities is the Bochumer Bruch, www.bochumer-bruch.de
but you will have to register to climb there and pay a fee.
Still you have pretty decent crags and bouldering spots about 1h - 1 1/2h hours away by car.
Most of the routes here are bolted very well.
In the Sauerland area some crag developments have taken place in recent years.
You will find nice crags near the Biggesee lake, a perfect combination for hot summer weekends. "unterer Elberskamp in Heggen", "Borghauser Wand in Borghausen", "Scharpenbeul" in Windebruch
(Campsites on the lakeshore)
visit
www.kletterarena.info - again only in german, detailed topos
I know there are some great bouldering spots in the Eifel in Ettringen,
the crags over there are more trad-oriented because the volcanic rock forms a lot of cracks, but there are bolted routes as well.
And last but not least, there are many many climbing gyms in the rhine-cologne area and in the ruhr-area.
There are also many artificial outdoor climbing walls.
Meet other climbers at the local alpine club section www. alpenverein.de
they will have some better beta for you.
You