You can select objects to include in your output by using the Object Options and Object List, or the Edit Output mode. Objects that are part of an output are displayed in the Object List. For each selected object, you can decide if you want it to be visible in the final render or not. Non-renderable objects, such as cameras, are always included in outputs.

To select an object:
In the Object List, click an object.
Selected objects are highlighted in the Object List, schematic, and image window.
To select additional objects, Ctrl-click another object.
To output all objects:
In the Object Options, enable All Objects.
All objects in the scene, as well as any object you subsequently create, are included in the selected output.
To set the visibility of an object:
Renders the object as black, excluding it from the shading effect. The result is a perceptual hole where the object was originally located.
Renders the object in the final render.
To add or remove an object from the Object List:
From the Tools box, select Edit Output.
Add or remove objects from the output by doing one of the following in the schematic:
To set all objects to Visible mode:
Click Reset All.
All objects in the selected output are set to the Visible mode.
Enable to output all objects in the Object List.
Select a visibility option for the selected object.
Click to set all objects to Visible mode in the Object List.