If you don't mind waiting, there are a couple of good places to order gaming material in English. One is Amazon.de, which has a lot of WotC stuff and some of the smaller developers as well. Drawbacks? It takes 1-2 weeks, usually. Also, you have to know some German or someone who can translate for you while you order. Shipping is free if the total order is more than €30.
Another place that has everything, the people are friendly, and it doesn't take too long as long as you do not order any Pinnacle stuff (my last order took 6 weeks, while they waited for a Pinnacle product to come in, but they had Spycraft after 1 week). Again, you might have to know German... though chances are they speak English, so they can help you out.
The link:
Pegasus.
Edit: Just thought of another ordering option that has come in handy for me.
The Warehouse 23 which is run by Steve Jackson Games (or at least affiliated with them) has a whole ton of gaming-related material, though not WotC or most of the D&D-related stuff. I ordered from them a couple times and was happy to see my order arrive from the US in 7 business days, and only costing $5 shipping per product, which is CHEAP when ordering from the US. So, if you can't get something any other way, that is a decent way to go.
I live in Frankfurt, and I only know one good gaming store here. Not at all sure about Munich itself.
You get used to the keyboard. Just don't switch back and forth between English and German keyboards! You will hit the Z key everytime you want a Y and vice versa -- no matter which one you are using!
