For more information about true reflections, see True reflections.
To create true (photorealistic) reflections, you must raytrace the scene, a process which can take a significant amount of time. For more information about raytracing, see Depth map and raytraced shadows.
You must have at least two surfaces to create true reflections (or a surface that somehow curves around so one part of its surface can reflect onto another part of its surface).
You can control which surfaces appear in reflections and which don’t by turning Visible in Reflections on or off in each surface’s Attribute Editor. (Visible in Reflections is on by default when you create new surfaces.)
To create true reflections (example)
This tells Maya to raytrace any surface whose Visible in Reflections/Refractions is toggled on. These attributes are on by default for all surfaces, but raytracing only works when you turn on Raytracing in the Render Settings window.
To learn more about the Render Settings, see Render Settings window.
To test iterations of a scene, see Visualize interactively with IPR.