Head Angle

As a relative newbie, I'm intrigued by all the discussion here about head angle. Would someone like to fill me in as to what makes a "good" head angle?

IMO having the head parallel to the image plane or facing the image plane makes for a stronger image than having the head tuned away.

Thanks, James. That makes perfect sense to me.

Have a peep here, Ian :). http://www.birdphotographers.net/for...ead.php?t=7781

Thanks, Tony. That's exactly the kind of tutorial I was looking for!