The microstructure and rheological properties of a model colloidal system was probed in the vicinity of the glass transition by small-angle and ultra small-angle x-ray scattering, dynamic light scattering (DLS) and bulk rheology. The volume fraction of the particles was deduced by modeling the structure factor and the absolute scattered intensity in a self-consistent way. The glass transition (phi(G)) was identified from the frequency dependence of the shear moduli in the linear regime. The experimentally observed behavior was then compared with the viscoelastic properties derived from mode-coupling theory (MCT) using the experimental structure factor as input to the theory. The ensemble-averaged intermediate scattering functions from DLS measurements were also compared with those calculated from the MCT and reasonable agreement was obtained.