I will present the results from multi-wavelength observations of a calibration sample of high-redshift quasars that were obtained during the past six years. These observations provided the largest uniform inventory of rest-frame ultraviolet-optical spectral properties for quasars at `cosmic noon', a treasure trove that is facilitating numerous quasar and cosmological studies. In this talk, I will focus on two principal investigations that we have been carrying out at UNT. The first involves improved ultraviolet-based redshift estimates for distant quasars, and the second involves improved estimates of the masses and accretion rates of supermassive black holes (SMBHs) residing in the centers of quasars. I will conclude by describing how a newly approved extension of this project in the next three years will bring us closer to understanding SMBH growth in the early universe.