To contribute to the CPAN, you need two things:
Something to contribute, hopefully already in the shape of a module
A Perl Authors Upload Server (PAUSE) ID
The PAUSE ID is your ticket to contributing to the CPAN. You get a PAUSE ID just for the asking. The details are described at http://www.cpan.org/modules/04pause.html. You need to fill out a web form (linked from there) with a few basic details such as your name, home web page, email address, and your preferred PAUSE ID. At the moment, PAUSE IDs must be between four and nine characters. (Some legacy PAUSE IDs are only three characters long.)
 Originally, the PAUSE IDs had to be five characters or less, until Randal wanted his MERLYN ID, and the appropriate accommodation was made.
Once you have your PAUSE ID, you need to think globally about your contribution. Because your module will probably be used in programs along with other modules from other authors, you need to ensure that the package names for modules don't collide or confuse. Consult with the module-naming volunteers listening at the email@example.com mailing list to get a name or hierarchy of names for your module or related modules.
Before you send your first email to the module czars, it's probably a good idea to do a few things first:
Look at the current module list. Get an idea for how things are named. Better yet, are you just reinventing a subset of something that already exists, or can you simply contribute your work as a patch to another module?
Visit the list archives (pointers can be found at http://lists.perl.org) to see what the typical conversations look like. That might help you to avoid shock at your response, or better phrase your initial request.
Above all, get it in your head that this whole process is run by volunteers who aren't perfect and are doing this in their spare time for the good of the Perl community. Have patience. Have tolerance.