Studies of W and Z Bosons with the CMS Detector at the CERN LHC

We present the preparatory work on the measurement of the W and Z production cross section and the use of the Z sample as a "candle" for physics and detector commissioning with the first LHC data. The studies target the early understanding of the W and Z production at the LHC. They provide handles for data-driven extraction of Standard Model backgrounds to New Physics Searches, a direct probe of New Physics, and a benchmark for testing relevant QCD calculations.