I'm not clear on how to start a service when the server boots, I read on some of the other questions asked about adding the script to /etc/init.d, but It's just one line that I need to execute in the commandline:

sudo /etc/init.d/avahi-daemon restart

But I have a few issues with this, firstly, I apparently need to use sudo, and it gives me the following:

ngl-server-01:~% sudo /etc/init.d/avahi-daemon start  
Rather than invoking init scripts through /etc/init.d, use the service(8)
utility, e.g. service avahi-daemon start

Since the script you are attempting to invoke has been converted to an
Upstart job, you may also use the start(8) utility, e.g. start avahi-daemon

But when I try just avahi-daemon start I get:

Too many arguments

Why is this? and how would you start this service?