Move in towards the center of the view
Select Zoom 
.
-OR-
Roll the middle mouse button forward to zoom in. Roll the middle mouse button backward to zoom out.
-OR-
Press CTRL + SHIFT + Z.
Magnify an area of the view
-
Select Zoom Area
on View Manipulation Toolbar at the bottom of the active view.
-
Select and drag a fence around the area to fill the view.
Drag the zoom area off the edge of the window to pan the view as you define the zoom
area.