A PDF document is a non editable document that keeps all of your fonts and colors. If you were to create a Word document and use a specific font, that font may not be on the next machine you open the document. For this reason, we suggest printing to PDF.
The nice part about OS X is that from ANY application you can turn your document into a PDF by printing it to a PDF.
In order to do this, select print from the file menu and you get a screen similar to the following:
Notice the button at the bottom that says "Save as PDF". Select that button. You will then be given your standard save dialog box where you can name the file and pick the location to save it at.
Once you hit save, you have created your pdf document.