As a VERY new player aka n00b to SWTOR, I wanted to know which is the best Tank Class to choose, from what I've read here, it seems Shadow/Assasin would be the best for a n00b l.ike me?
Yes, Shadow FTW.
I'll jump on the "ShadowsTanksAreHardToPlay" boat for a minute and argue that if you master the hardest class, you'll have very little problems adapting to the "easier" classes.
Back to reality - Shadow is terribly easy to play. As is the enire game.