Margins & Rule of Thirds
Use Rectangles/Guides
Use a Rectangle to Make 1/2 Inch Margins
Select the Rectangle Tool
Click on the artboard to bring up the "Rectangle" pop-up
Adjust:
Width: 7.5 in
Height: 10 in
Click OK
In the "Properties" tab, under Align, click the third and sixth icon to "Horizontal Align Center" and "Vertical Align Center"
Right-click on the rectangle and lcikc "Make Guides"
Use a Rectangle to Make a Rule of Thirds Grid
Use the Rectangle Tool to create a rectangle to fill your whole artboard.
With the rectangle selected, click "Object" > "Path" > "Split Into Grid..."
Change:
Rows
Number: 3
Columns:
Number: 3
Click "OK"
Right-click on the grid and click "Make Guides"
Lock Guides
In the "Properties" tab, next to "Guides" click the middle icon with the lock on it to lock your guides.
Use Rulers/Guides
Turn on Rulers
In the "Properties" tab on the right:
Make sure the "Units" is set to "Inches"
Next to "Rulers & Grids" section, click the first icon (looks like a right angle corner) to turn on rulers.
You should now see darker gray rulers at the top and left of the window.
Create Guides
Click, hold, and drag from the rulers on the left and top to create guides (bright blue lines).
These guides are only in Illustrator - meaning they won't save on a PDF or when you export.
You can click on guides in order to edit them.
Guides span across all artboards.
Use Guides to Make Margins
To use guides to make margins:
Drag from the left ruler twice to create the left and right margins
Drag from the top ruler twice to create the top and bottom margins.
Create a Rule of Thirds Grid
Click and drag from the rulers on the left and top to create guides (bright blue lines).
Create guides so that you have a 3x3 grid
Horizontal: drag down from the top and create guides around 3.75" and 7.5"
Vertical: drag across from the left and create guides around 2.75" and 5.75"
In the right toolbar, next to "Guides" click the middle icon with the lock on it to lock your guides.
Lock Guides
In the "Properties" tab, next to "Guides" click the middle icon with the lock on it to lock your guides.