A review of the state-of-the-art of electron transport theory and calculations for electrons in the energy range below 10 MeV is presented. The basic interactions that influence the behavior of electrons are reviewed and theory and experimental results are compared wherever possible. The continuous slowing down model, the straggling model, and multiple scattering models are discussed and their use in thick-target moments method and Monte Carlo calculations is described. Results of the thick-target calculations are also compared with experimental results. Included in the review is a detailed description of the various complex-geometry electron transport programs presently being used.