These notes provide an introduction to polarization effects in deep inelastic processes in
QCD. We emphasize recent work on transverse asymmetries, subdominant effects, and the
role of polarization in fragmentation and in purely hadronic processes. After a review of
kinematics and some basic tools of short distance analysis, we study the twist, helicity,
chirality and transversity dependence of a variety of high energy processes sensitive to the
quark and gluon substructure of hadrons.