The Sloan Digitized Sky Survey (SDSS) and the proposed Sloan Extension for Galactic Understanding and Evolution (SEGUE) offer a unprecedented stellar database with which to explore the properties of the thin disk, thick disk, and halo of the Galaxy. To make full use of the information contained in the available spectra and photometry, we require external checks on determinations of radial velocity, temperature, surface gravity, and metal abundance for stars in the SDSS/SEGUE database. One useful approach is to make use of the large number of globular cluster stars that have been (or will be) observed in SDSS/SEGUE. As examples, we present color-magnitude diagrams, in the SDSS ugriz system, for four galactic globular clusters, M 2, M 13, M 15, and NGC 2419, based on photometry reported in the third SDSS public data release, DR-3. These data are compared with recent isochrones suitable for old, metal-poor clusters of the halo population. In addition, as part of tests being conducted for SEGUE, we have obtained medium-resolution (2.3 Å ) spectra for some 30 likely members of the cluster M 15. These data are used to provide an independent check on the accuracy with which we can estimate the radial velocities and atmospheric parameters (Teff, log g, [Fe/H]) for SDSS stars that will be obtained during the course of SEGUE. This work received partial funding support from grant PHY 02-16783, Physics Frontier Centers/JINA: Joint Institute for Nuclear Astrophysics, awarded by the US National Science Foundation. C.R. acknowledges support from NASA grant HST-HF-01143.01-A.