Just a heads up that Scribus 1.4.4 now support exporting PDFs in PDF/x-1a format. You can download it from here.
Why is this important? Many Print on Demand companies works best with PDFs in the PDF/x-1a format. This is a special variant of PDFs that guarantees that the layout especially color will print out as expected on the printers that support the standard.
The word processors, publishing programs, and similar software that are available to the typical home users do not feature this as it requires support of color spaces and similar high end features. For those of us who just trying to use the PoD features of RPGNow and DriveThruRPG or Amazon's Createspace, we just want the PDF in the right format.
The trick is to setup your Scribus document to use color management. Most folks don't need to fret about the choices just go with the defaults.
Also it would help to have a affordable desktop publishing program to help do the layout. Luckily Scribus is free and open source. It not the easiest desktop publishing program to learn but with 1.4.4 it has acquired the necessary features to make it of use for a small RPG publisher.
Also don't forget the following
AbiWord for writing
Gimp for image editing
Inkscape for vector images like maps.