I've installed Nero Linux 3.0.12 OK, but can't figure out how to install the keygen. I'm not very experienced at using the command line. The instructions are as follows:

1) open a terminal
2) chmod +x keymaker
3) ./keymaker
4) cd /
5) tar xvzf /path/to/nerolinux-3.0.0.0-x86.tar.gz
6) start nerolinux and enter a serial

If someone could walk me through this that would be great. Thanks.

Sorry, but this would be unethical and probably illegal to help you run this commercial package by generating a key/serial number crack. You can always buy it for $19.99 from Nero.

Any reason why you don't use a Linux based burning software? There are several good ones out there depending on the desktop and distro that you are running.