Learning System Administration: What to focus on?

In the fall I am taking courses in System Admin and Networking Admin, along with Cisco classes. Sometime next year I hope to get Red Hat and CCNA certifications, then try to get some experience and a job.

I am wondering what I can focus on in the meantime (and in my spare time) that will contribute to my knowledge of systems administration.

I have some experience with C++, PHP and MySql programming but they're not really related to SysAdmin.

I was thinking learning Perl would be more helpful. Or if I could do some type of project. I'd appreciate any other ideas though. I would like to focus on something that I can put to use and/or gain experience in SysAdmin.

Any ideas would be appreciated.

Knowing the bourne shell is essential for UNIX system administration, I think, since you will be spending a lot of time in it.

Perl is less essential, and sometimes unhelpful if you use it to approach problems from the wrong angle -- looking at some of my old Perl scripts, they are line after line after line of system("shell program"); By just writing them properly in shell I could have made them two thirds smaller and 90% simpler.