Next-to-leading order corrections to
jet cross sections in deep inelastic scattering at HERA are
studied.
The predicted jet rates allow for a precise
determination of $\alpha_s(\mu_R)$ at HERA over a wide range of
$\mu_R$.
We argue, that the ``natural'' renormalization and
factorization scale is set by the average $k_T^B$
of the jets in the Breit frame and suggest to
divide the data in corresponding $<k_T^B>$ intervals.
Some implications
for the determination of the gluon density and
the associated forward jet production in the low $x$ regime at HERA
are briefly discussed.
