Early LHC data preparations for beyond-the-standard-model searches at CMS

Searches for supersymmetry (SUSY) and other phenomena beyond the standard model involve a broad range of signatures with jets, leptons, photons, and missing transverse momentum (MET). These searches require careful control over backgrounds from standard model processes. We present several methods for data-driven background determinations that have been tested on early LHC data collected by the CMS experiment at $\sqrt{s}=7$ TeV. These data allow us to study QCD backgrounds, to evaluate methods to suppress the effects of jet-energy mis-measurement, to validate data-driven methods for predicting the MET distribution, and to measure background contributions from processes producing fake leptons.