Biodegradable plastics/polymers may serve as a promising solution to the global problem of plastic waste accumulation in oceans and soil and may significantly reduce carbon emissions from the manufacturing process, since the materials used to make biodegradable polymers are carbon-based and emitted during the synthesis processes. This article systematically reviewed the existing and closely related scientific literature on materials, biomaterials, and biodegradable materials to find answers on how to effectively study and develop biodegradable polymers. This article reviewed and summarized the source classifications of the biodegradable plastics. Some of the major manufacturing techniques for making biodegradable polymer products were discussed, including micro-extrusion for biofibers, solvent casting method for thin films, 3D printing, injection and compression molding and extrusion processes, as well as the fabrication methods applied to some important biopolymers, such as cellulose, starch, bacterial concrete, packaging materials, and paper-based biodegradable materials. More importantly, experimental and computational methodologies applied for materials characterization and development that can be adopted to characterize the properties of biodegradable polymers and understand the physicochemical mechanisms of the materials were described in detail, including experimental methods (physical and chemical methods) and computational methods at different scales (from quantum mechanics at subatomic scale, molecular dynamics at atomic scale, to finite element analysis at micro or macro scale), and data analysis methods. The degradation mechanisms and factors affecting the biodegradability of the polymers were discussed. Finally, the future perspective of biodegradable polymers has been described. Properly adopting the effective state-of-the-art biomaterial research and characterization techniques (experimental and computational methods) and advanced data analysis methods discussed in this article will help advance the development of novel biodegradable polymers.