  We investigate different aspects of lattice QCD in Landau gauge using Monte
Carlo simulations. In particular, we focus on the low momentum behavior of
gluon and ghost propagators. The gauge group is SU(3). Different systematic
effects on the gluon and ghost propagators are studied, e.g. the dependence on
the choice of Gribov copies or the influence of dynamical Wilson fermions. We
compare our data with results from studies of Dyson-Schwinger equations for the
gluon and ghost propagators. We demonstrate that the infrared behavior of both
propagators, as found in this thesis, is consistent with different criteria for
confinement. However, the running coupling constant, given as a
renormalization-group-invariant combination of the gluon and ghost dressing
functions, does not expose a finite infrared fixed point. We also report on a
first nonperturbative computation of the SU(3) ghost-gluon-vertex
renormalization constant and on an investigation of the spectral properties of
the Faddeev-Popov operator.
