I use a small piece of software called PDFCreator that lets me print a file to a "printer" that converts the file into a PDF. It preserves things like text and links that can be copied or clicked on, just as in any other PDF.
http://sourceforge.net/projects/pdfcreator/
I wanted to post this because some people may want to make PDF versions of documents that look nice for distribution to sponsors and school administrators, uploading as a whitepaper, or posting on websites. My team used PDFCreator for a distributable version of our Chairman's essay.
Sometimes image quality doesn't look great in the PDF from this software; other times it's ok. I really don't know anything about using professional software to make a PDF. This is just something I happened to find a year or two ago. I know there's other free software out there that does this--if you use anything good, post it here.