You can control the camera movement with the standard WASD control system commonly used in First Person Shooters.
When the mouse pointer is within the window, hold down the right mouse button and move the mouse pointer to rotate the view.
Hold down the middle mouse button and move the mouse pointer to pan the view.
Roll the middle mouse button wheel to move the view forward or backward.
Hold down Shift to double the speed of the viewport movements.
The Speed: input is used to increase or decrease the movement speed of all the movements you make in the main Perspective Viewport.
The 3 buttons to the right of the Speed: <input> are shortcuts to the .1 1 and 10 speeds. You can also manually set the speed by typing into the box, or by using the two arrows to adjust the speed up or down.
This button toggles terrain collision for the perspective camera. When turned on, the camera will not move below the terrain, but slide along.