This thesis, a mainly expository work, attempts to give all the calculational details for some popular models in scalar quantum eld theory that serve a mostly pedagogical purpose. Starting with a real scalar eld with a given Lagrangian in classical eld theory, standard quantization results given in most introductory QFT texts are derived with as many explicit calculations (which are often left to the reader) as possible. After presenting this development, we gather speci c calculations that model scattering and decay processes. In many texts, the author(s) simply gives one or two calculations as an example. Here we organize several di erent calculations in a single work.