Primo PDF

I highly recommend Primo PDF, an application that allows you to create PDFs for free. I've never used Adobe Acrobat or the like, so I can comment on the comparative quality. For the price, however, I think this is a great deal. I've used it to share sheet music that I prepared in my cheap notation program. Once it's installed, all you have to do is print your document, but select Primo PDF as your "printer."