The official README that also comes with the source package can be found here.
Daniel Herfort from macademy provided a package that allows using CUPS-PDF on recent versions of MacOS X with sandboxing including a brief Readme how to make it work.
Doc Walker compiled a SELinux HowTo along with required files.
For the installation of CUPS-PDF on OpenSolaris x86 a comprehensive HowTo has been compiled by Esteban Fallas.
A quick guide (in German, but easily comprehensible without knowledge in German) for the installation on OpenIndiana can be found on the webpage of Philipp Speck.
Thomas Müller provided a CUPS-PDF HOWTO (as MS Word File) on how to set up CUPS-PDF in combination with Windows Active Directory Services (ADS), Windows Domains and language-specific special characters (e.g. German umlauts). The HOWTO is at this time only available in German but since it contains many examples it can be helpful even without the need to be able to read German.
A Galician and a Spanish installation HOWTO can be found on www.diazdelaiglesia.com.
Now you will be able to choose "CUPS-PDF (Virtual PDF Printer)" when setting up a new printer in CUPS (a CUPS-restart may be necessary).
To set up a queue for other UNIX clients you should select Postscript as vendor and the Color Printer as model for your new printer; queues that get their input from samba or netatalk (i.e. Windows, OS/2 or MacOS) can be set up as raw queues. On the Windows, OS/2 or MacOS system choose a color postscript driver for that network printer (the drivers for Minolta Page Works or HP DesignJet printers do a good job).
Hint: If you want to create grayscale PDFs you just have to choose a grayscale printer driver, i.e. the postscript.ppd that comes with CUPS on the Linux side or a b/w laser printer (e.g. a HP LaserJet) on the Windows side. On the Linux side be aware that the postscript.ppd will not re-process data that is already supplied in Postscript format, i.e. a color Postscript will keep its colors.
Once you print to the new device the output directory selected in cups-pdf.conf (defaults to /var/spool/cups-pdf) will be created and all converted PDF files will be placed in subdirectories named after the owner of the print job. In case the owner cannot be identified (i.e. does not exist on the server) the output is placed in the directory for anonymous operation (if not disabled in cups-pdf.conf - defaults to /var/spool/cups-pdf/ANONYMOUS/). Furthermore if logging is enabled the logfile will be placed by default in /var/log/cups.
The files "CUPS-PDF_opt.ppd" and "CUPS-PDF_noopt.ppd" are modified versions of the "Postscript.ppd" that comes with CUPS 1.1.15 that is able to handle color output.