To move forward, backward, turn left and turn right:

Click & hold the left mouse button in the simulation window, and drag up, down, left, and right respectively

To see a description of an item

Point to it with the mouse for about a second

To look upward

Press "8" on the numeric keypad (the "up arrow")

To look downward

Press "2" on the numeric keypad (the "down arrow")

To move your eye level upward

Press "9" on the numeric keypad (the "Pg Up" key)

To move your eye level downward

Press "3" on the numeric keypad (the "Pg Dn" key)

To zoom in on something

Press the space bar

To zoom out to a wide-angle view

Press the "B" key