Before you do any kind of rendering, you'll need to set some render options. Rendering options are set for the scene, for your renderer of choice (by default this is set to mental ray), and for each render pass you define.
For interactive preview renders, the render region has its own set of renderer options. See Previewing Interactively with the Render Region.
This section provides an overview of the different types of render options, and explains how to access them. It also describes how to use the Render manager — a dedicated view for multi-editing your render options.
