Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
when you have the document you want to convert to a pdf open, go to file, then print.

i'm not on a mac right now, but from what I recall, there should be a button that says, Save as PDF. Click that and that should be it.

someone please correct me if i'm wrong.

daniel
 
Select Print from the File menu in any application. In the bottom left hand corner of the Print window will be a PDF button. Hit that, select Save to PDF and name your file.

EDIT : Beaten to it by Dandaman, who is most correct in his answer.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.