To be honest, running linux on your ipod doesn't have many "pros" to be completely honest (aside from being able to play doom on it and the novelty, which gets old considering how difficult it is to do anything useful).
If you'd like to run linux on your ipod, as stated above, ipodlinux is the easiest way to do this. Not sure if much has changed since I did it, but I had to play around with partitions and stuff to install it (potentially dangerous if you don't know what you're doing).
As someone who has ran multiple OSes on my ipod (5G) I recommend http://www.rockbox.org/
Rockbox is an Open Source OS for your ipod that is super easy to install, and will unlock some things (such as being able to play FLAC) on you ipod (its also pretty much impossible to screw up, and you can easily restore your ipod with iTunes if you do).
If you still have your hopes set on linux, feel free to give it a shot (it is, at the very least, a learning experience). The project seems pretty dead these days though, so you might have trouble finding support.