The Dutch g is pronounced in one of two ways,
depending on who's speaking and where. It's
either the same as the German "ach-laut" in
"Bach" and the Scottish "loch," or it's the
exact same sound voiced. The "voiced" part is
the difference between the English k (unvoiced
palatal plosive) and the English g (voiced
palatal plosive). The ach-laut is an unvoiced
palatal fricative, and the Dutch g, when not
pronounced the same as the ach-laut, is a
voiced palatal fricative.

I spent weeks and weeks walking around trying
to train myself to make the voiced version,
scaring lots of people in the process, and
when I finally got to the Netherlands, everyone
I heard speaking Dutch was using the unvoiced
version. My time would have been better spent
on Dutch vocabulary.

Another thing to watch out for is the ch sound.
In German it's pronounced one of two ways, but
in Dutch it's only pronounced one way (the same
as the ach-laut, and never voiced.)

--John
with an otherwise unused BA in German