Do you want to know how to create PDF documents? To be honest its as easy as printing the document you want to create. If you don't already know what PDF documents are, its an application independent file format that allows the document to be read without the original application it was created with.
There is an application called PDF995, that is basically a printer driver that captures the output from almost any application and converts it into a non-editable PDF document. This applications comes in two versions, free or paid. The paid version only costs $9.95, and the free version requires you to view advertisements each time you use it.