Secondary and tertiary states of fluid flow in a layer between two plates in relative motion and rotating about a normal axis of rotation are studied numerically for a wide range of parameters. Plane Couette flow without rotation and the single Ekman layer at a rigid plate above a quiescent fluid half-space are obtained as limiting cases. A Galerkin method is used for the investigation of the bifurcation structures of the problem. A Chebyshev collocation scheme is used for following the evolution of time-dependent states of the flow. Comparisons are made with experimental observations as well as with previous studies of particular parameter limits.