An easy way to create PDF files is to use iTextSharp. It is an opensource PDF library that allows to you generate PDF files on the fly. It's great if you need to dynamically create a PDF using dynamic data. Also, I found that this is a great tool to easily make barcodes. You can create common barcodes such as Code 128, Code 39, EAN 128, and Code 39 ext.
I've included a copy of a small project that I've whacked together using the library which shows how to create a barcode in a PDF.