You can use horizontal and vertical guides as a
straight-edge, to align and place objects precisely. When an edge
or the center of an object gets close to a guide, that edge or
center automatically snaps to the guide.
To set up guidelines:
Choose View
| Guidelines Setup.
To run the guideline horizontally
across your page, click Horizontal.
Enter a position (distance from
the top of your page) for the guideline, and click Set.
To run the guideline vertically
down your page, click Vertical.
Enter a position (distance from
the left edge of your page) for the guideline, and click Set.