An overview of various modeling methods used to understand small angle neutron scattering (SANS) data from homogeneous polymer systems is presented. First, calculations of single macromolecule structure factors are reviewed for many chain architectures and monomer block configurations such as linear, ring, star branched, comb grafted chains and regular “starburst” dendrimers either in the homopolymer or copolymer forms. Then, the different methods used to model “concentration” effects in polymer solutions (dilute, semidilute, concentrated), polymer melts and blend mixtures are summarized on the basis of the random phase approximation. Polymer chain stiffness is also included in the formalism so that mixtures of liquid crystals and flexible polymers in the single-phase region can be described. Specific examples are included along with various SANS data that were analyzed within this framework. This overview is meant to be a guide to help build up models in order to understand SANS data from many homogeneous polymer systems. It is not meant to be complete and is not an exhaustive review of the literature in the field. Most of the results discussed have been previously published and are brought together here in a unified self-contained approach.