re: Licensing you could do a lot worse than a creative commons license. A creative commons attribution license would fit what you've asked for. You could also tack on non-commercial and share-alike provisions if you like.
I concur with Babau - maybe the one you want is the CC by-nc-sa (Attribution, Non-commercial and Share-Alike). The Share-alike provision is SORT OF similar to the GPL, in that any derivative works must also be under the same Share-alike. The Non-Commercial provision guarantees that people can't reprint your work and sell it on a commercial basis, without your permission 1st.
You should be fine with the German version of 2.0. There's not enough amazing stuff in 3.0 to warrant using the generic version over the German one. You can always update to the German 3.0 when it's out if you feel a pressing need to.