  We consider reflection and transmission of polarized paraxial light beams at
a plane dielectric interface. The field transformations taking into account a
finite beam width are described based on the plane-wave representation and
geometric rotations. Using geometrical-optics coordinate frames accompanying
the beams, we construct an effective Jones matrix characterizing
spatial-dispersion properties of the interface. This results in a unified
self-consistent description of the Goos-H\"anchen and Imbert-Fedorov shifts
(the latter being also known as spin-Hall effect of light). Our description
reveals intimate relation of the transverse Imbert-Fedorov shift to the
geometric phases between constituent waves in the beam spectrum and to the
angular momentum conservation for the whole beam. Both spatial and angular
shifts are considered as well as their analogues for the higher-order vortex
beams carrying intrinsic orbital angular momentum. We also give a brief
overview of various extensions and generalizations of the basic beam-shift
phenomena and related effects.
