The diffuse cosmological background light that pervades our Universe continues to be one of the best probes to uncover the astrophysical environments of the early Universe. In our attempt to gain a more holistic understanding of our present cosmological situation, we seek to understand the formation and evolution of the first stars and galaxies that came into existence. It is thought that these first-light galaxies are the progenitors to our Milky Way, and all other evolved galaxies. The spatial fluctuations of the extragalactic background light trace the total emission from all stars and galaxies in the Universe, and these first-light galaxies have left a measurable imprint on the cosmic infrared backgroud (CIB) light. In the first part of this thesis I describe measurements which suggest a detection of this signal, using a large subset of data from the largest allocation of Hubble time to date (CANDELS). This is followed by a cross-correlation analysis of the CIB with the cosmic X-ray background (CXB), which can give some insight as to whether or not X-ray emitting sources were present during this first-light epoch. I then shift towards the far-infrared (submillimeter) regime and discuss a statistical measurement of the redshift distribution of Herschel galaxies. Finally I show two-point correlation measurements of strongly lensed submillimeter galaxies, and the bias that this population may be introducing into past and current clustering analyses, which can lead to erroneous dark matter halo mass measurements from such studies.