There are several ways to create PDF files but the best is to use a program called Acrobat Distiller. Distiller was written by Adobe, the company that invented the PDF format, and it does the most reliable job of producing PDF files that can be read on any computer.
Detailed instructions appear below.
Also, if you are using some form of TeX there are a few additional things you'll need to consider listed at the bottom of the page. The first step in using it, therefore, is to create a PostScript version of your document. The instructions from this point on depend on what operating system you are using. Once you have a PostScript file it's easy to create the PDF version. The distill command does not use a graphical interface so you don't have to be up in the lab to use it.