  We discuss the prospects for setting limits on or discovering spin-1 $Z'$
bosons using early LHC data at 7 TeV. Our results are based on the narrow width
approximation in which the leptonic Drell-Yan $Z'$ boson production
cross-section only depends on the $Z'$ boson mass together with two parameters
$c_u$ and $c_d$. We carefully discuss the experimental cuts that should be
applied and tabulate the theoretical next-to-next-to-leading order corrections
which must be included. Using these results the approach then provides a safe,
convenient and unbiased way of comparing experiment to theoretical models which
avoids any built-in model dependent assumptions. We apply the method to three
classes of perturbative $Z'$ boson benchmark models: $E_6$ models, left-right
symmetric models and sequential standard models. We generalise each class of
model in terms of {mixing angles which continuously parametrize} linear
combinations of pairs of generators and lead to distinctive orbits in the
$c_u-c_d$ plane. We also apply this method to the strongly coupled four-site
benchmark model in which two $Z'$ bosons are predicted. By comparing the
experimental limits or discovery bands to the theoretical predictions on the
$c_u$-$c_d$ plane, we show that the LHC at 7 TeV with integrated luminosity of
500 pb$^{-1}$ will greatly improve on current Tevatron mass limits for the
benchmark models. If a $Z'$ is discovered our results show that measurement of
the mass and cross-section will provide a powerful discriminator between the
benchmark models using this approach.
