  The gold-plated discovery mode of a Standard Model like Higgs boson at the
CERN Large Hadron Collider (LHC) is the H -> Z^0 Z^0 decay mode. To find and
then measure the properties of the Higgs, it is crucial to have the most
precise theoretical prediction both for the signal and the QCD background in
this mode. In this work we calculate the effects of the initial-state multiple
soft-gluon emission on the kinematic distributions of photon and Z^0 pairs
produced in hadron collisions. The Collins-Soper-Sterman formalism is extended
to resum the large logarithmic terms due to soft-gluons. The resummed total
rates, the invariant mass, transverse momentum, and rapidity distributions of
the photon and Z^0 pairs, and the transverse momentum distributions of the
individual vector bosons are presented and compared to the fixed order
predictions in the whole kinematic range, for the LHC energies and for the
upgraded Fermilab Tevatron. Our conclusion is that the resummed predictions
should be used when extracting the Higgs signal at the LHC.
