  The production of $W^{\pm}$ bosons in longitudinally polarized
$\vec{p}+\vec{p}$ collisions at RHIC provides a new means of studying the
spin-flavor asymmetries of the proton sea quark distributions. Details of the
$W^{\pm}$ event selection in the $e^{\pm}$ decay channel at mid-rapidity are
presented, along with preliminary results for the production cross section and
parity-violating single-spin asymmetry, $A_L$, from the STAR Collaboration's
2009 data at $\sqrt{s}=500$ GeV.
