Yes, I guess when there is time the src.rpm is added to the repos.
Glad you ask about becoming a packager :-) This section is package suggest so we should move this discussion elsewhere, but:
If you have a spare machine you can use it for packaging, but else start by creating a virtual machine - see the sticky's in the Packagers section http://www.pclinuxos.com/forum/index.php/board,55.0.html
I can recommend to create a 30-40 GB virtual machine using VMWare. This will take an evening or two to setup.
Install a small PCLinuxOS into the virtual machine, update it. Enable the 'testing' repo and install pkgutils. Then remove 'testing' repo again. I have added some nifty packaging features to Thunar's (filemanager) servicemenus (right-click) so you could try installing pkgutils-thunar.
You will end up with a ~/src folder that has the necessary folders inside it.
Start out slowly by updating smaller packages, and if all work out then contact Tex to get access to his srpm Dropbox where we put updated srpm's.
You will run into a bunch small and larger questions, but just ask away in the packagers section and you are welcome to pm me with questions,