  Measurements of galaxy cluster abundances, clustering properties, and mass
to- light ratios in current and future surveys can provide important
cosmological constraints. Digital wide-field imaging surveys, the
recently-demonstrated fidelity of red-sequence cluster detection techniques,
and a new generation of realistic mock galaxy surveys provide the means for
construction of large, cosmologicallyinteresting cluster samples, whose
selection and properties can be understood in unprecedented depth. We present
the details of the "maxBCG" algorithm, a cluster-detection technique tailored
to multi-band CCD-imaging data. MaxBCG primarily relies on an observational
cornerstone of massive galaxy clusters: they are marked by an overdensity of
bright, uniformly red galaxies. This detection scheme also exploits classical
brightest cluster galaxies (BCGs), which are often found at the center of these
same massive clusters. (ABRIDGED)
