how to register ipod nano 5 gen

Recently, I have purchased ipod nano 5 gen and connect it to my laptop through itune. For the first time, it ask for registration which I escaped by thinking that I will do that later. However, when I have connected next time, no registration form appear. I want to know whether I can register my ipod now manually using online connection. I am using ipod first time and completely unaware of the whole process. Can anyone give fruitful suggestion.