How do you make a pdf?

[Steven M. Sawczyn]

With zillions of pdf files on my Mac, I'm surprised that I don't see a  
utility for creating one.  I'm writing a short how to of sorts and  
have been asked to create it as a pdf file, ideally, with sections  
divided into an outline, the way I've seen various help files and  
manuals done.  Does anyone know how to do this?  is there a utility  
somewhere that I'm just missing?

Thanks,
Steve