Production of graphene from graphene oxide (GO), having properties similar to pristine graphene, is the most challenging task so far in the graphene sector. Finding an ideal reduction method that can remove oxygen-containing functionalities while repairing the lattice defects present in GO is essential. Thermal annealing of GO with an additional carbon source has emerged as a viable solution for this issue where reduction of GO can be conducted with the simultaneous restoration of lattice defects. Herein, we review this topic in-depth, in terms of morphological, structural, and electrical properties of GO films, basically, for the development in the field of graphene-based electronic devices.