There are lots of free PDF program around if you don't have Acrobat, one you could use is PDF creator.
Creates a virtual printer (PDF) so u cud convert
Open the file (it can be anything that you're able to print to like a normal printer). It can be a word document, image, etc. Then click on File --> Print. Instead of selecting your default printer, choose from the drop-down menu, "CutePDF" instead. Click Print, and it'll ask you where you want the PDF file to be saved.
I prefer you to use CutePDF.It allows you to create PDF files from any printable document, save PDF forms using Acrobat Reader, make PDF booklet, impose, rearrange pages and much more