Do I need a resistor in circuit which isn't calling for it?
Yes you always need some sort of circuit to limit current and a resistor is the simplest.
See:-
http://www.thebox.myzen.co.uk/Tutorial/LEDs.html
Ignore a member dhenry who will pop up and tell you diffrently, he delights in giving advice that damages peoples machines.
this high intensity blue LED.
So what is the current rating? LEDs of over 50mA or so need a constant current supply rather than a resistor.