Map Navigation Help
Choose the map type in the top right corner. Click and drag to move around the map. Use the mouse scroll wheel to zoom in and out.
Navigating in Google Earth (free plugin is required)
Move the view in any direction	To move the view, position the mouse cursor on the viewer and press the LEFT mouse button. Notice that the cursor icon changes from an open hand to a closed hand . Pull the viewer as if the hand cursor is like a hand on an actual globe, and you want to drag a new part of the earth into view.
Zoom in / out	Use the mouse scroll wheel to zoom in and out.
Rotate the view	Rotate the view by pressing the mouse wheel or middle button and moving the mouse around. You can also press Shift and the left mouse button and drag.
Look	To look around from a single vantage point, as if you were turning your head, press Ctrl and left mouse button and drag.

For more information check the Google Earth website