Editing objects, layout parts, and the layout background > Using tools to precisely position objects > Using guides and dynamic guides
 
Using guides and dynamic guides
You can use guides and dynamic guides to help you create and edit objects on a layout.
Use horizontal and vertical guides to align objects on one or across multiple layouts.
Use dynamic guides to align objects to one another on a layout. When you drag objects, dynamic guides appear near or on other objects. Dynamic guides also snap to the upper and lower boundaries and the centers of objects as you move, resize, or position them.
Guides and dynamic guides on a layout
 
To
In Layout mode, do this
Create a vertical guide or horizontal guide
Drag out from the vertical ruler, or drag down from the horizontal ruler. (If the ruler isn’t displayed, select View menu > Rulers.)
Move a guide
Drag the guide to the new position.
If a guide is locked, you must unlock it before you can move it.
Use guides in other layouts you create or edit
Right-click the guide, then choose Share Guide with All Layouts.
To use a shared guide only with the current layout, right-click the guide, then choose Share Guide with All Layouts again.
Lock or unlock a guide
Right-click the guide, then choose Lock Guide. A locked guide is a different color from an unlocked guide.
Remove a guide
Drag a horizontal guide back to the horizontal ruler, or a vertical guide back to the vertical ruler.
Or, right-click the guide, then choose Remove Guide.
Show or hide the guides
Choose View menu > Guides > Show Guides.
Turn the snap-to effect on or off
Choose View menu > Guides > Snap to Guides. Objects snap to guides even when the guides are hidden.
Turn dynamic guides on or off.
Choose View menu > Dynamic Guides.
Notes 
Objects snap to layout part boundaries when View menu > Guides > Snap to Guides is selected.