  We study $4$-dimensional SQCD with gauge group $SU(N_c)$ and $N_f$ flavors of
chiral super-multiplets on the lattice. We perform extensive calculations of
matrix elements and renormalization factors of composite operators in
Perturbation Theory. In particular, we compute the renormalization factors of
quark and squark bilinears, as well as their mixing at the quantum level with
gluino and gluon bilinear operators. From these results we construct correctly
renormalized composite operators, which are free of mixing effects and may be
employed in non-perturbative studies of Supersymmetry. All our calculations
have been performed with massive matter fields, in order to regulate the
infrared singularities which are inherent in renormalizing squark bilinears.
Furthermore, the quark and squark propagators are computed in momentum space
with nonzero masses.
  This work is a feasibility study for lattice computations relevant to a
number of observables, such as spectra and distribution functions of hadrons,
but in the context of supersymmetric QCD, as a forerunner to lattice
investigations of SUSY extensions of the Standard Model.
