On the Create panel, click Cameras, then on the Object Type rollout, activate Free.
Click the viewport location where you want the camera to be.
The kind of viewport you click determines the free camera's initial direction: The initial direction is along the negative Z axis of the active construction grid of the viewport you click.
The camera is now part of the scene.
Set the creation parameters.
Rotate and move the camera to adjust the point of view. (Or change a viewport to a Camera view, and use the viewport controls.)