good place to start messing with Linux
I'm new to Linux, (using about 3 months). I obviously have a grasp of basic commands and regularly read the man pages. But what i would like to know is what can I do to start changing the kernel. I've had my intro into software and installation and now I want to poke around with the actual OS, but I don't know where would be a good (safe) place for me to make changes.