When creating newsletters or laying out copy for magazine or newspaper I've found that these three shortcut keys can be perfect, time-saving helpers.

Apple/Control-D
~Places text or file within a box, allows you to select the file from anywhere within the computer files, eliminates unnecessary copy and pasting between programs and makes for a cleaner final product

Apple/Control-B
~Once you've placed text within a box this shortcut allows you to change column arrangement and number, perfect for newsletter and newspaper design

Apple/Control-Y
~Another shortcut to help with text placing, once text is placed you can use this shortcut to open a text-only file of what you've already placed, making it easy to access all of the text and see in size increments how much text you have within a box, also cuts down on box jumping for connected text boxes