>> Is there any site about German surnames' etymology?
>
> If there is, I haven't found it yet.
Bahlow, Hans, Deutsches Namenslexikon, 1967ff (e.g. Suhrkamp, 1972,
ISBN 3518365657), 1991
Kohlheim, Rosa & Volker, Familiennamen. Duden, 2005 (ISBN 3411708514)
Kunze, Konrad, dtv-Atlas Namenkunde (ISBN 3423032669)
Naumann, Horst, Das grosse Buch der Familiennamen (Bassermann, ISBN
3809407291)