No, Noob and Newbie are completely different things. Noob means your a stupid, ignorant, immature asshole. Newb means your new.
Wrong, she said n00b. With the zeros in place of the O, [short for newbie]. That's "teh internet speak".
Urban dictionary would like to disagree with those noobs: http://www.urbandictionary.com/define.php?term=noob&r=f